Supplemental spine fixation device and method

ABSTRACT

A supplemental spine fixation device and method is used in association with a primary spine fixation device. The supplemental spine fixation device includes a guide and spacer for distracting apart adjacent spinous processes and the device has hook members which hook about the first and second spinous processes. With the spinous processes distracted and the hook members about the spinous processes, the hook members can be rigidly secured to a hub in order to rigidly affix the spinous processes about the spacer. The rigidity between the spinous processes assures that the vertebral bodies will be held rigidly in place in order to promote bone growth and fusion. Further additional freedom of movement between the spacer and hub is accomplished with the spacer being pivotably mounted relative to the hub. The hooks have a tissue distracting lead-in guide for allowing the hooks to be easily urged between spinous processes.

PRIORITY CLAIM

This U.S. patent application is a divisional application of U.S. patentapplication Ser. No. 09/842,819, filed Apr. 26, 2001, entitledSUPPLEMENTAL SPINE FIXATION DEVICE AND METHOD; U.S. patent applicationSer. No. 09/842,819 claims priority from U.S. Provisional PatentApplication, 60/219,985, filed Jul. 21, 2000, and is acontinuation-in-part of U.S. patent application Ser. No. 09/579,039,filed on May 26, 2000 and entitled SUPPLEMENTAL SPINE FIXATION DEVICEAND METHOD, which is a continuation-in-part of U.S. patent applicationSer. No. 09/473,173 filed on Dec. 28, 1999 and entitled SPINEDISTRACTION IMPLANT, now U.S. Pat. No. 6,235,030 issued May 22, 2001,which is a continuation of U.S. patent application Ser. No. 09/179,570filed on Oct. 27, 1998 and entitled SPINE DISTRACTION IMPLANT, now U.S.Pat. No. 6,048,342 issued Apr. 11, 2000, which is a continuation-in-partof U.S. patent application Ser. No. 09/175,645 filed on Oct. 20, 1998and entitled SPINE DISTRACTION IMPLANT, now U.S. Pat. No. 6,068,630issued May 30, 2000, which is a continuation-in-part of U.S. patentapplication Ser. No. 08/958,281 filed on Oct. 27, 1997 and entitledSPINE DISTRACTION IMPLANT AND METHOD, now U.S. Pat. No. 5,860,977 issuedJan. 19, 1999, which is a continuation-in-part of U.S. patentapplication Ser. No. 08/778,093 filed Jan. 2, 1997 entitled SPINEDISTRACTION IMPLANT AND METHOD, now U.S. Pat. No. 5,836,948 issued Nov.17, 1998. All of the above applications and patents are incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention is directed to supplemental spine fixation devicesand methods which are used as an adjunct to a primary spine fusiondevice, such as by way of example only, an interbody fusion device.

BACKGROUND OF THE INVENTION

A common procedure for handling pain associated with degenerative spinaldisk disease is the use of devices for fusing together two or moreadjacent vertebral bodies. The procedure is known by a number of terms,one of which is interbody fusion. Interbody fusion can be accomplishedthrough the use of a number of devices and methods known in the art.These include screw arrangements, solid bone implant methodologies, andfusion devices which include a cage or other mechanism which is packedwith bone and/or bone growth inducing substances. All of the above areimplanted between adjacent vertebral bodies in order to fuse thevertebral bodies together, alleviating associated pain.

Associated with such primary fusion devices and methods are supplementaldevices which assist in the fusion process. These supplemental devicesassist during the several month period when bone from the adjacentvertebral bodies is growing together through the primary fusion devicein order to fuse the adjacent vertebral bodies. During this period it isadvantageous to have the vertebral bodies held immobile with respect toeach other so that sufficient bone growth can be established.

Such supplemental devices can include hook and rod arrangements, screwarrangements, and a number of other devices which include straps, wires,and bands, all of which are used to immobilize one portion of the spinerelative to another.

All of these devices generally require extensive surgical procedures inaddition to the extensive procedure surrounding the primary fusionimplant.

It would be advantageous if the device and procedure for supplementalspine fixation were as simple and easy to perform as possible, and wouldleave intact all bone, ligament, and other tissue which comprise andsurround the spine.

Accordingly, there needs to be developed procedures and implants whichare minimally invasive and are supplemental to spine fixation devicesand methods.

SUMMARY OF THE INVENTION

The present invention is directed to providing a minimally invasivesupplemental spine fixation implant and method for alleviatingdiscomfort associated with the spine.

The present invention provides for a method and apparatus for assistingin the fusing together of vertebral bodies of the spine. One of thefeatures and purposes of the invention is to immobilize the vertebralbodies while spine fusion is accomplished. Generally fusion requiresupwards of six months for bone cells from the upper and lower vertebralbodies to grow towards each other, generally through a primary fusiondevice.

In order to assist in the fusing process, the supplemental spinalfixation device and method of the invention immobilizes the vertebralbodies by immobilizing the respective spinous processes extendingtherefrom. In addition, the present invention and method can be used todistract apart the posterior sides of the vertebral bodies in order toput additional force and compression on the anterior sides of thevertebral bodies, further assisting in the interbody fusion process.

The present invention and method is minimally invasive such that it doesnot add to the trauma of the primary fusion procedure, especially if thefusion procedure is from a posterior approach. With an anterior fusionapproach additional posterior incisions are required. However, these areminimal when compared to other devices and methods.

Accordingly an object of the present invention is to increase therigidity and stability with respect to the adjacent spinous process andvertebral bodies in order to promote interbody fusion between thevertebral bodies. It is further an object of the present invention to beas minimally invasive as possible.

It is yet a further object of the present invention to provide for animplant and method which does not require modification of the bone,ligaments, or adjoining tissues. In other words, it is an object of thepresent invention to provide for an implant and method which does notrequire that the bone be reshaped, notched, or in anyway modified.Further it is an object of the present invention to provide for animplant and method which does not require that any of the ligamentsassociated with the spinous processes be altered.

It is a further object of the present invention to provide for animplant and method which can be inserted from one side of adjacentspinous processes, in order to immobilize the spinous processes andresultingly immobilize the adjacent vertebral bodies. By addressing thespinous processes from one side, the objects and advantages of aminimally invasive procedure, with reduced trauma, can be accomplished.

It is another object of the present invention to provide for a deviceand method which provides for distraction of the spinous processes inorder to place pressure on at least the anterior portion of thevertebral bodies in order to assist in the primary fusion.

It is still a further object of the present invention to provide for animplant and method which can increase the space between spinousprocesses in order to adjust the height between vertebral bodies.

It is yet a further object of the present invention to provide for adevice which has securing and/or hook elements which can easily andconveniently be secured about the spinous processes, which hook devicesare preferably designed in order to accommodate the shape of the spinousprocesses and are preferably swivelable or pivotable in order toaccommodate the position and shape of one spinous processes relative toanother.

It is another object of the invention to provide for a device which hasseveral degrees of freedom in order to allow a portion of the device tobe positioned between spinous processes in order to distract apart thespinous processes and other portions of the device to engage the spinousprocesses in order to rigidly immobilize the spinous processes. Thesedegrees of freedom allow the device to conform to the bones, ligaments,and tissues of each individual patient. Thus, the present device allowsfor adjustments along two and three axises in order to successfullydistract and immobilize spinous processes.

It is yet a further object of the present invention to have at least oneportion of the device selectably positionable with respect to otherportions of the device in order to accommodate the anatomy of the spineand in particular of the spinous processes.

It is still a further object of the present invention to provide for adevice and method which can be used with both primary anterior orposterior interbody fusion.

Accordingly, it is an object and aspect of the invention to provide adevice and method for augmentation of single or multiple level lumbarspinal fusion. Ideally the fusion and the device and method of thisinvention are addressed at the L4/L5 vertebral bodies and above, andalso at the L5/S1 vertebral bodies. The device and method can also beused with other vertebral bodies located along the spine.

The present invention provides for rigidity without risk to the neuralelements. The present invention is cost effective and minimallyinvasive.

Accordingly, an aspect of the present invention includes an implant forrigidly positioning spinous processes, which implant includes a firstmeans adapted for engaging the first spinous process and a second meansadapted for engaging the second spinous process. The implant includes abody means adapted for positioning between the first spinous process andthe second spinous process and a hub means for engaging the first means,the second means, and the body means.

Further, the invention includes at least one of the hub means and thebody means allowing for the body means to move relative to at least oneof the first and second means.

In a further aspect and object of the present invention, an implantincludes a first hook adapted to engage a first spinous process and asecond hook adapted to engage a second spinous process. The implant hasa body adapted to the position between the spinous processes and a hubto which mounts the first and second hooks and the body. The body ismoveable relative to at least one of the first and second hooks.

It is further an aspect and object of the present invention to providean implant for rigidly positioning spinous processes as an adjunct tospine fusion, where the improvement includes a sleeve position betweenadjacent spinous processes.

It is a further aspect of the present invention to provide an implantfor rigidly positioning spinous processes as an adjunct to spine fusionwherein the improvement comprises a sleeve or spacer positioned betweenadjacent spinous processes and a first hook which is adapted to engage afirst spinous process and a second hook which is adapted to engage asecond spinous process.

The method of the present invention is for rigidly positioning a firstspinous process relative to a second spinous process and includes thesteps in any desired order of placing a first hook around a firstspinous process and a second hook around a second spinous process. Thesteps include placing a sleeve or spacer between the first and secondspinous processes, which spacer mounts to a hub. The hub is used tointerlock the first hook relative to the second hook.

It is a further object of the present invention to provide asupplemental spine fixation device and method which has additionalfreedom in the placement of the hooks and the spacer relative to thehub. In one aspect of the invention, the spacer is mounted on a shaftrelative to hub and is pivotable about a pivot point relative to thehub. This is in addition to the spacer being rotatable about the shaftrelative to the hub in a particular embodiment.

The hook themselves have a lead-in nose which is adapted to separatetissues between the spinous process in order to allow the hook to beurged into engagement with a spinous process.

In another aspect of the invention, the hub is designed in order to onassembly, lock in the spacer and the hooks by locking in the shafts uponwhich they are mounted.

In still a further aspect of the invention, the spacer is egg-shaped inorder to accommodate the shape of the spinous process and the spacethere between. In a further aspect of the invention, in particular withrespect to the egg-shaped spacer, the spacer has a bore therethrough onwhich the spacer can rotate, which bore is offset, being closer to theblunt end of the shape spacer than the pointed end. This allows thespacer to have the pointed end positioned closer to the spine.According, more surface area of the spacer supports the spinousprocesses in areas where the spinous processes are stronger.

Other embodiments of the implants and methods, within the spirit andscope of the invention, can be understood by a review of thespecification, the claims, and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1 and 2 depict an embodiment of an implant of the invention whichis adjustable in order to select the amount of distraction required.FIG. 1 depicts the implant in a more extended configuration than doesFIG. 2.

FIGS. 3 a and 3 b depict side and end views of a first forked and of theembodiment of FIG. 1.

FIGS. 4 a and 4 b depict side sectioned and end views of an interbodypiece of the implant of FIG. 1.

FIGS. 5 a and 5 b depict side and end views of a second forked end ofthe embodiment of FIG. 1.

FIGS. 6, 7, 8, 9 and 10 depict apparatus and method for anotherembodiment of the present invention for creating distraction betweenadjacent spinous processes.

FIGS. 11, 12 and 13 depict yet a further embodiment of the invention forcreating distraction between adjacent spinous processes.

FIGS. 14 and 15 depict a further apparatus and method of an embodimentof the invention for creating distraction.

FIGS. 16, 16 a, and 17 depict yet another embodiment of the presentinvention.

FIGS. 18, 19 and 20 depict yet a further apparatus and method of thepresent embodiment.

FIGS. 21 and 22 depict still a further embodiment of the presentinvention.

FIGS. 23, 24 and 25 depict another embodiment of the present invention.

FIGS. 26, 27 and 28 depict another embodiment of the invention.

FIGS. 29 and 30 depict side elevational views of differently shapedimplants of embodiments of the present invention.

FIGS. 31, 32 and 33 depict various implant positions of an apparatus ofthe present invention.

FIGS. 34 and 35 depict yet another apparatus and method of the presentinvention.

FIGS. 36, 37 and 38 depict three different embodiments of the presentinvention.

FIGS. 39 and 40 depict yet another apparatus and method of an embodimentof the present invention.

FIGS. 41, 42 and 43 depict yet further embodiments of an apparatus andmethod of the present invention.

FIG. 44 is still a further embodiment of an implant of the invention.

FIG. 45 is yet another depiction of an apparatus and method of theinvention.

FIGS. 46 and 47 depict still a further apparatus and method of anembodiment of the invention.

FIGS. 48, 49, 50 and 51 depict yet a further apparatus and method of theinvention.

FIGS. 52, 53, 54, 55 a and 55 b depict another apparatus and method ofthe invention.

FIGS. 56, 57 and 58 depict yet a further apparatus and method of theinvention.

FIGS. 59 and 60 depict still a further embodiment of the invention.

FIG. 61 depict another embodiment of the invention.

FIGS. 62 and 63 depict yet another embodiment of the present invention.

FIGS. 64 and 65 depict still a further embodiment of the presentinvention.

FIG. 66 depicts an other embodiment of the invention.

FIGS. 67 and 68 depict yet another embodiment of the present invention.

FIGS. 69, 70, 71 and 71 a depict a further embodiment of the presentinvention.

FIGS. 72 and 73 depict still another embodiment of the invention.

FIGS. 74, 75, 76, 77, and 78 depict still other embodiments of theinvention.

FIGS. 79, 80, 80 a, 81, 82, 83, 83 a, 84, 85, 86 and 87 depict still afurther embodiment of the present invention.

FIGS. 88, 89, 90 and 91 depict yet another embodiment of the presentinvention.

FIGS. 92, 92 a, 92 b, 93, 93 a, 93 b, 93 c, 93 d, 94, 94 a, 94 b, 95, 95a, and 96, depict still a further embodiment of the present inventionwherein a sleeve is provided which is capable of deflecting response torelative motion between the spinous processes.

FIG. 97 depicts still another embodiment of the present invention.

FIG. 98 depicts yet a further embodiment of the present invention.

FIGS. 99 and 100 depict still another embodiment of the presentinvention including an insertion tool.

FIGS. 101, 102, 102 a, 103, 104, 105, 106, and 107 depict still afurther embodiment of the present invention.

FIGS. 108, 109, and 110 depict still another embodiment of the presentinvention.

FIGS. 111, 112, 113, 114, 115, 116, and 117 depict yet anotherembodiment of the present invention.

FIG. 118 depicts a graph showing characteristics of a preferred materialusable with several of the embodiments of the present invention.

FIGS. 119 a and 119 b depict side and plan views of still a furtherembodiment of the present invention.

FIGS. 120 a and 120 b depict side and plan views of the second wingwhich can be used in conjunction with the embodiment of the invention ofFIGS. 119 a and 119 b.

FIGS. 121 a and 121 b depict side and plan views of the first wing andcentral body of the embodiment of the invention depicted in FIGS. 119 aand 119 b.

FIGS. 122 a, 122 b, and 122 c depict top, side and end views of a guidewhich is a portion of the embodiment of the invention of FIGS. 119 a and119 b.

FIGS. 123 a and 123 b depict an end view and a cross-sectioned viewrespectfully of the sleeve of the embodiment of the invention of FIGS.119 a and 119 b.

FIGS. 124 a, 124 b and 124 c depict a view of the embodiment of theinvention of FIGS. 119 a and 119 b taken through line 124-124 in FIG.119 b shown in with the sleeve in various positions relative to a firstwing.

FIG. 125 depicts an alternative embodiment of the invention as depictedin FIGS. 119 a and 119 b.

FIG. 126 depicts yet a further alternative embodiment of the inventiondepicted in FIGS. 119 a and 119 b.

FIG. 127 depicts yet a further embodiment of the invention as depictedin FIGS. 119 a and 119 b.

FIG. 128 is still a further embodiment of the invention as depicted inFIG. 93 a.

FIG. 129 depicts still a further embodiment of the invention as depictedin FIGS. 119 a and 119 b.

FIG. 130 is a perspective view of a first embodiment of the invention.

FIG. 131 is an exploded view of the embodiment of the invention of FIG.130. FIGS. 131 a and 131 b are alternative components of the embodimentof FIG. 131.

FIG. 132 is a plan view of the embodiment of the invention of FIG. 130.

FIGS. 133 a, 133 b, 133 c, and 133 d are perspective, first end, secondend, and sectional views of a spacer or sleeve of the embodiment of theinvention depicted in FIG. 130.

FIG. 134 is a cross sectional view of an embodiment of the inventiontaken through line 134-134 in FIG. 132.

FIGS. 135 a-135 f are various views of an embodiment of the hookmechanism of the embodiment of the invention of FIG. 130.

FIG. 136 is a schematical representation of an embodiment of theinvention as positioned with respect to adjacent spinous processes.

FIG. 137 is a perspective view of another embodiment of the invention.

FIG. 138 is an exploded view of the embodiment of the invention of FIG.137.

FIG. 138 a is an alternative component of the embodiment of FIG. 137.

FIG. 138 b is an upside down perspective view of a component of theembodiment of FIG. 138.

FIG. 139 is a plan view of the embodiment of the invention of FIG. 137.

FIG. 140 is a partial section view taken through line 140-140 of FIG.139.

FIG. 141 is an exploded view of yet another embodiment of the invention.FIG. 141 a is an upside down perspective view of a component of theembodiment of FIG. 141.

FIG. 142 is a sectional view of a body portion of the embodiment of theinvention of FIG. 141 taken through line 142-142.

FIG. 143 is a top view of the body portion shown in FIG. 142.

FIG. 144 is a sectional view of yet another embodiment of a body portionof the invention.

FIG. 145 is a perspective view of yet a further embodiment of the bodyportion of the invention.

FIGS. 146 a, 146 b, and 146 c depict yet a further embodiment of a bodyportion of the invention.

FIGS. 147 a and 147 b are side and top views of yet another embodimentof the invention depicting a mechanism for adjusting the positions ofthe hook mechanisms of, for example, the embodiment of the invention ofFIGS. 130, 137, and 141.

FIGS. 148 a and 148 b are sectional top and side views of yet anotherembodiment of the invention for adjusting the position of the hookmechanisms.

FIGS. 149 a and 149 b are perspective and side views of yet a furthermechanism of an embodiment of the invention for adjusting the positionof hook mechanisms of the invention.

FIG. 150 is a perspective view of yet a further embodiment of theinvention.

FIG. 151 is a perspective view of an embodiment of the invention whichis addressable to multiple levels of spinous processes.

FIG. 152 is a perspective view of an alternative embodiment of thesupplemental spine fixation device of the invention.

FIG. 153 is an exploded view of the embodiment of the invention of FIG.152.

FIG. 154 a is a sectioned view of the spacer and lead-in nose tissueexpander of the invention.

FIG. 154 b is an end view of a spacer of FIG. 154 a.

FIG. 154 c is an exploded view of several of the components of FIG. 154a.

FIG. 155 a is a plan, partially sectioned view of an embodiment of ahook of the invention.

FIG. 155 b is a sectioned view taken through line 155 b-155 b of FIG.155 a.

FIG. 155 c is a sectioned view taken through line 155 c-155 c of FIG.155 a.

FIG. 155 d is a bottom view of the embodiment of the hook of theinvention of 155 a.

FIG. 155 e is an end view of FIG. 155 d.

FIG. 156 is a view of an embodiment of a shaft arrangement of theinvention upon which hooks can be mounted.

FIG. 157 is an alternate view of the top member of the hub showing thelocking mechanism.

FIGS. 158 a and 158 b are sectioned views of an alternate embodiment ofthe hub mechanism of the invention.

FIG. 159 is an alternate embodiment of the hook attached to a shaft ofthe invention.

FIG. 160 is an alternate embodiment of a sleeve of the inventionpositioned between adjacent spinous processes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention, although directed to embodiments for providingsupplemental spine fixation devices and methodologies depicted in FIGS.130 to 160, have some of the same functionalities, features, designcharacteristics, and materials as previously described in theembodiments depicted and described in FIGS. 1 to 129. FIGS. 1 to 129 aredirected to spine distraction implant and method used in distractingapart spinous processes in order to relieve pain associated with thespine such as, by way of example only, the pain associated with spinalstenosis. Accordingly, as appropriate, and even if not specificallymentioned in each inventive description of FIGS. 130 to 160, many of thedesign characteristics, features, functionalities, materials,measurements, dimensions, purposes, aspects, and objects of the devicesin FIGS. 1 to 129 are applicable to the present invention.

Embodiments of FIGS. 1-5 a, 5 b

A first embodiment of the invention is shown in FIGS. 1-5 a, 5 b.Implant 20 includes first and second forked ends 22 and 24, eachdefining a saddle 26, 28 respectively. The forked ends 22, 24 are matedusing an interbody piece 30. As can be seen in FIGS. 3 a, 3 b, the firstforked end 22 includes a threaded shaft 32 which projects rearwardlyfrom the saddle 26. The threaded shaft 32 fits into the threaded bore 34(FIG. 4 a) of the interbody piece 30.

The second forked end 24 (FIGS. 5 a, 5 b) includes a smooth cylindricalshaft 36 which can fit into the smooth bore 38 of the interbody piece30.

FIG. 1 shows the implant 20 in a fully extended position, while FIG. 2shows the implant in an unextended position. In the unextended position,it can be seen that the threaded shaft 32 of the first forked end 22fits inside the hollow cylindrical shaft 36 of the second forked end 24.

For purposes of implantation between adjacent first and second spinousprocesses of the spinal column, the implant 20 is configured as shown inFIG. 2. The first and second spinous processes are exposed usingappropriate surgical techniques and thereafter, the implant 20 ispositioned so that saddle 26 engages the first spinous process, andsaddle 28 engages the second spinous process. At this point, theinterbody piece 30 can be rotated by placing an appropriate tool or pininto the cross holes 40 and upon rotation, the saddle 26 is movedrelative to the saddle 28. Such rotation spreads apart or distracts thespinous processes with the resultant and beneficial effect of enlargingthe volume of the spinal canal in order to alleviate any restrictions onblood vessels and nerves.

It is noted that this implant as well as the several other implantsdescribed herein act as an extension stop. That means that as the backis bent backwardly and thereby placed in extension the spacing betweenadjacent spinous processes cannot be reduced to a distance less than thedistance between the lowest point of saddle 26 and the lowest point ofsaddle 28. This implant, however, does not inhibit or in any way limitthe flexion of the spinal column, wherein the spinal column is bentforward.

Preferably, such a device provides for distraction in the range of about5 mm to about 15 mm. However, devices which can distract up to and above22 mm may be used depending on the characteristics of the individualpatient.

With all the ligaments (such as the superspinous ligament) and tissuesassociated with the spinous processes left intact, the implant 20 can beimplanted essentially floating in position in order to gain the benefitsof the aforementioned extension stop and flexion non-inhibitor. Ifdesired, one of the saddles 26 can be laterally pinned with pin 29 toone of the spinous processes and the other saddle can be looselyassociated with the other spinous processes by using a tether 31 whicheither pierces or surrounds the other spinous process and then isattached to the saddle in order to position the saddle relative to thespinous process. Alternatively, both saddles can be loosely tethered tothe adjacent spinous process in order to allow the saddles to moverelative to the spinous processes.

The shape of the saddles, being concave, gives the advantage ofdistributing the forces between the saddle and the respective spinousprocess. This ensures that the bone is not resorbed due to the placementof the implant 20 and that the structural integrity of the bone ismaintained.

The implant 20 in this embodiment can be made of a number of materials,including but not limited to, stainless steel, titanium, ceramics,plastics, elastics, composite materials or any combination of the above.In addition, the modulus of elasticity of the implant can be matched tothat of bone, so that the implant 20 is not too rigid. The flexibilityof the implant can further be enhanced by providing additional aperturesor perforations throughout the implant in addition to the holes 40 whichalso have the above stated purpose of allowing the interbody piece 30 tobe rotated in order to expand the distance between the saddle 26, 28.

In the present embodiment, it is understood that the spinous processescan be accessed and distracted initially using appropriateinstrumentation, and that the implant 20 can be inserted and adjusted inorder to maintain and achieve the desired distraction. Alternatively,the spinous process can be accessed and the implant 20 appropriatelypositioned. Once positioned, the length of the implant can be adjustedin order to distract the spinous processes or extend the distraction ofalready distracted spinous processes. Thus, the implant can be used tocreate a distraction or to maintain a distraction which has already beencreated.

The placement of implants such as implant 20 relative to the spinousprocess will be discussed hereinbelow with other embodiments. However,it is to be noted that ideally, the implant 20 would be placed close tothe instantaneous axis of rotation of the spinal column so that theforces placed on the implant 20 and the forces that the implant 20places on the spinal column are minimized.

Further, it is noted that during the actual process of installing orimplanting the implant 20, that the method uses the approach ofextending the length of the implant 20 a first amount and then allowingthe spine to creep or adjust to this distraction. Thereafter, implant 20would be lengthened another amount, followed by a period where the spineis allowed to creep or adjust to this new level of distraction. Thisprocess could be repeated until the desired amount of distraction hasbeen accomplished. This same method can be used with insertion toolsprior to the installation of an implant. The tools can be used to obtainthe desired distraction using a series of spinal distraction and spinecreep periods before an implant is installed.

Embodiments of FIGS. 6, 7, 8, 9 and 10

The embodiment of the invention shown in the above FIGS. 6, 7, 8, 9 and10 includes distraction or spreader tool 50 which has first and secondarms 52, 54. Arms 52, 54 are pivotal about pivot point 56 andreleaseable from pivot point 56 in order to effect the implantation ofimplant 58. As can be seen in FIG. 6, in cross-section, the arms 52, 54are somewhat concave in order to cradle and securely hold the firstspinous process 60 relative to arm 52 and the second spinous process 62relative to arm 54. The distraction tool 50 can be inserted through asmall incision in the back of the patient in order to address the spacebetween the first spinous process 60 and the second spinous process 62.Once the tool 50 is appropriately positioned, the arms 52, 54 can bespread apart in order to distract the spinous processes. After this hasoccurred, an implant 58 as shown in FIGS. 8 and 9, or of a design shownin other of the embodiments of this invention, can be urged between thearms 52, 54 and into position between the spinous processes. After thisoccurs, the arms 52, 54 can be withdrawn from the spinous processesleaving the implant 58 in place. The implant 58 is urged into placeusing a tool 64 which can be secured to the implant 58 through athreaded bore 66 in the back of the implant. As can be seen in FIG. 10,the implant 58 includes saddles 68 and 70 which cradle the upper andlower spinous processes 60, 62 in much the same manner as the abovefirst embodiment and also in much the same manner as the individual armsof the tool 50. The saddles as described above tend to distribute theload between the implant and the spinous processes and also assure thatthe spinous process is stably seated at the lowest point of therespective saddles.

Embodiments of FIGS. 11, 12 and 13

Another embodiment of the apparatus and method of the invention is shownin FIGS. 11, 12 and 13. In this embodiment, the spreader or distractiontool 80 includes first and second arms 82, 84 which are permanentlypivoted at pivot point 86. The arms include L-shaped ends 88, 90.Through a small incision, the L-shaped ends 88, 90 can be insertedbetween the first and second spinous processes 92, 94. Once positioned,the arms 82, 84 can be spread apart in order to distract the spinousprocesses. The implant 96 can then be urged between the spinousprocesses in order to maintain the distraction. It is noted that implant96 includes wedged surfaces or ramps 98, 100. As the implant 96 is beingurged between the spinous processes, the ramps further cause the spinousprocesses to be distracted. Once the implant 96 is fully implanted, thefull distraction is maintained by the planar surfaces 99, 101 locatedrearwardly of the ramps. It is to be understood that the cross-sectionof the implant 96 can be similar to that shown for implant 58 or similarto other implants in order to gain the advantages of load distributionand stability.

Embodiments of FIGS. 14, 15, 16, 16 a, and 17

In FIGS. 14 and 15, yet another embodiment of the invention is depicted.In this embodiment, the implant 110 includes first and second conicallyshaped members 112, 114. Member 112 includes a male snap connector 116and member 114 includes a female snap connector 118. With male snapconnector 116 urged into female snap connector 118, the first member 112is locked to the second member 114. In this embodiment, a distraction orspreader tool 80 could be used. Once the spinous process has been spreadapart, an implantation tool 120 can be used to position and snaptogether the implant 110. The first member 112 of implant 110 is mountedon one arm and second member 114 is mounted on the other arm of tool120. The member 112, 114 are placed on opposite sides of the spacebetween adjacent spinous processes. The members 112, 114 are urgedtogether so that the implant 110 is locked in place between the spinousprocesses as shown in FIG. 15. It is to be noted that the implant 110can also be made more self-distracting by causing the cylindricalsurface 122 to be more conical, much as surface 124 is conical, in orderto hold implant 110 in place relative to the spinous processes and alsoto create additional distraction.

An alternative embodiment of the implant can be seen in FIGS. 16 and 17.This implant 130 includes first and second members 132, 134. In thisparticular embodiment, the implants are held together using a screw (notshown) which is inserted through countersunk bore 136 and engages athreaded bore 138 of the second member 134. Surfaces 139 are flattened(FIG. 17) in order to carry and spread the load applied thereto by thespinous processes.

The embodiment of implant 130 is not circular in overall outsideappearance, as is the embodiment 110 of FIGS. 14 and 15. In particular,with respect to the embodiment of implant 130 of FIGS. 16 and 17, thisembodiment is truncated so that the lateral side 140, 142 are flattenedwith the upper and lower sides 144, 146 being elongated in order tocapture and create a saddle for the upper and lower spinous processes.The upper and lower sides, 144, 146 are rounded to provide a moreanatomical implant which is compatible with the spinous processes.

If it is desired, and in order to assure that the first member 132 andthe second member 134 are aligned, key 148 and keyway 150 are designedto mate in a particular manner. Key 148 includes at least one flattenedsurface, such as flattened surface 152, which mates to an appropriatelyflattened surface 154 of the keyway 150. In this manner, the firstmember is appropriately mated to the second member in order to formappropriate upper and lower saddles holding the implant 130 relative tothe upper and lower spinous processes.

FIG. 16 a depicts second member 134 in combination with a rounded noselead-in plug 135. Lead-in plug 135 includes a bore 137 which can fitsnugly over key 148. In this configuration, the lead-in plug 135 can beused to assist in the placement of the second member 134 between spinousprocesses. Once the second member 134 is appropriately positioned, thelead-in plug 135 can be removed. It is to be understood that the lead-inplug 135 can have other shapes such as pyramids and cones to assist inurging apart the spinous processes and soft tissues in order to positionthe second member 134.

Embodiments of FIGS. 18, 19 and 20

The implant 330 as shown in FIG. 18 is comprised of first and secondmating wedges 332 and 334. In order to implant these wedges 332, 334,the spinous processes are accessed from both sides and then a tool isused to push the wedges towards each other. As the wedges are urgedtowards each other, the wedges move relative to each other so that thecombined dimension of the implant 330 located between the upper andlower spinous processes 336, 338 (FIG. 20), increases, therebydistracting the spinous processes. It is noted that the wedges 332, 334include saddle 340, 342, which receiving the spinous processes 336, 338.These saddles have the advantages as described hereinabove.

The first or second wedges 332, 334 have a mating arrangement whichincludes a channel 344 and a projection of 346 which can be urged intothe channel in order to lock the wedges 332, 334 together. The channel334 is undercut in order to keep the projection from separatingtherefrom. Further, as in other devices described herein, a detent canbe located in one of the channel and the projection, with acomplimentary recess in the other of the channel and the projection.Once these two snap together, the wedges are prevented from slidingrelative to the other in the channel 344.

While the above embodiment was described with respect to wedges, thewedges could also have been designed substantially as cones with all thesame features and advantages.

Embodiments of FIGS. 21 and 22

The implant 370 is comprised of first and second distraction cone 372,374. These cones are made of a flexible material. The cones arepositioned on either side of the spinous processes 376, 378 as shown inFIG. 21. Using appropriate tool as shown hereinabove, the distractioncones 372, 374 are urged together. As they are urged together, the conesdistract the spinous processes as shown in FIG. 22. Once this hasoccurred, an appropriate screw or other type of fastening mechanism 380can be used to maintain the position of the distraction cones 372, 374.The advantage of this arrangement is that the implant 370 isself-distracting and also that the implant, being flexible, molds aboutthe spinous processes as shown in FIG. 22.

Embodiments of FIGS. 23, 24 and 25

In FIGS. 23 and 24, another embodiment of the implant 170 is depicted.This implant is guided in place using an L-shaped guide 172 which canhave a concave cross-section such as the cross-section 52 of retractiontool 50 in FIG. 6 in order to cradle and guide the implant 170 inposition. Preferably a small incision would be made into the back of thepatient and the L-shaped guide tool 172 inserted between the adjacentspinous processes. The implant 170 would be mounted on the end ofinsertion tool 174 and urged into position between the spinousprocesses. The act of urging the implant into position could cause thespinous processes to be further distracted if that is required. Prior tothe insertion of the L-shaped guide tool 172, a distraction tool such asshown in FIG. 13 could be used to initially distract the spinousprocesses.

Implant 170 can be made of a deformable material so that it can be urgedinto place and so that it can somewhat conform to the shape of the upperand lower spinous processes. This deformable material would bepreferably an elastic material. The advantage of such a material wouldbe that the load forces between the implant and the spinous processeswould be distributed over a much broader surface area. Further, theimplant would mold itself to an irregular spinous process shape in orderto locate the implant relative to spinous processes.

With respect to FIG. 25, this implant 176 can be inserted over a guidewire, guide tool or stylet 178. Initially, the guide wire 178 ispositioned through a small incision to the back of the patient to aposition between the adjacent spinous processes. After this hasoccurred, the implant is threaded over the guide wire 178 and urged intoposition between the spinous processes. This urging can further distractthe spinous processes if further distraction is required. Once theimplant is in place, the guide tool 178 is removed and the incisionclosed. The insertion tools of FIGS. 23 and 24 can also be used ifdesired.

Embodiments of FIGS. 26, 27 and 28

The embodiment shown in FIGS. 26, 27 and 28 uses an implant similar tothat depicted in FIGS. 8 and 9 with different insertion tools. As can beseen in FIG. 26, an L-shaped distraction tool 190 is similar to L-shapeddistraction tool 80 (FIG. 12), is used to distract the first and secondspinous processes 192, 194. After this has occurred, an insertion tool196 is placed between the spinous processes 192, 194. Insertion tool 196includes a handle 198 to which is mounted a square-shaped ring 200.

The distraction tool 190 can be inserted through a small incision in theback in order to spread apart the spinous processes. Through the sameincision which has been slightly enlarged laterally, an upper end 202 ofring 200 can be initially inserted followed by the remainder of the ring200. Once the ring is inserted, the ring can be rotated slightly bymoving handle 198 downwardly in order to further wedge the spinousprocesses apart. Once this has been accomplished, an implant such asimplant 204 can be inserted through the ring and properly positionedusing implant handle 206. Thereafter, the implant handle 206 and theinsertion tool 196 can be removed.

Embodiments of FIGS. 29, 30, 31, 32 and 33

As can be seen in FIGS. 29 and 30, the implants 210, 212, can havedifferent shapes when viewed from the side. These implants are similarto the above-referenced implants 58 (FIG. 8) and 204 (FIG. 28). Theseimplants have cross-sections similar to that shown in FIG. 10 whichincludes saddles in order to receive and hold the adjacent spinousprocesses.

As can be seen in FIGS. 31, 32 and 33, these implants can be placed indifferent positions with respect to the spinous process 214. Preferablyas shown in FIG. 33, the implant 210 is placed closest to the lamina216. Being so positioned, the implant 210 is close to the instantaneousaxis of rotation 218 of the spinal column, and the implant wouldexperience least forces caused by movement of the spine. Thus,theoretically, this is the optimal location for the implant.

As can be seen in FIGS. 31 and 32, the implant can be placed midwayalong the spinous process (FIG. 32) and towards the posterior aspect ofthe spinous process (FIG. 31). As positioned shown in FIG. 31, thegreatest force would be placed on the implant 210 due to a combinationof compression and extension of the spinal column.

Embodiments of FIGS. 34 and 35

Another embodiment of the invention is shown in FIGS. 34 and 35. Inthese figures, implant 220 is comprised of a plurality of individualleaves 222 which are substantially V-shaped. The leaves includeinterlocking indentations or detents 224. That is, each leaf includes anindentation with a corresponding protrusion such that a protrusion ofone leaf mates with an indentation of an adjacent leaf. Also associatedwith this embodiment is an insertion tool 226 which has a blunt end 228which conforms to the shape of an individual leaf 222. For insertion ofthis implant into the space between the spinous processes as shown inFIG. 29, the insertion tool 226 first insert a single leaf 220. Afterthat has occurred, the insertion tool then inserts a second leaf withthe protrusion 224 of the second leaf snapping into correspondingindentation made by the protrusion 224 of the first leaf. This processwould reoccur with third and subsequent leaves until the appropriatespacing between the spinous processes was built up. As can be seen inFIG. 29, the lateral edges 229 of the individual leaves 222 are slightlycurved upwardly in order to form a saddle for receiving the upper andlower spinous processes.

Embodiments of FIGS. 36, 37 and 38

The embodiments of FIGS. 36, 37 and 38 which include implants 230, 232,and 234 respectively, are designed in such a manner so the implant locksitself into position once it is properly positioned between the spinousprocesses. Implant 220 is essentially a series of truncated cones andincludes a plurality of ever expanding steps 236. These steps are formedby the conical bodies starting with the nose body 238 followed therebehind by conical body 240. Essentially, the implant 234 looks like afir tree placed on its side.

The implant 230 is inserted laterally throughout the opening betweenupper and lower spinous processes. The first body 238 causes the initialdistraction. Each successive conical body distracts the spinousprocesses a further incremental amount. When the desired distraction hasbeen reached, the spinous processes are locked into position by steps236. At this point, if desired, the initial nose body 238 of the implantand other bodies 240 can be broken, snapped or sawed off if desired inorder to minimize the size of the implant 230. In order for a portion ofthe implant 230 to be broken or snapped off, the intersection betweenbodies such as body 238 and 240, which is intersection line 242, wouldbe somewhat weaken with the appropriate removal of material. It is notedthat only the intersection lines of the initial conical bodies need tobe so weakened. Thus, intersection line 244 between the bodies whichremain between the spinous processes would not need to be weaker, asthere would be no intention that the implant would be broken off at thispoint.

FIG. 37 shows implant 232 positioned between upper and lower spinousprocesses. This implant is wedge-shaped or triangular shaped incross-sectioned and includes bore pluralities 245 and 246. Through thesebores can be placed locking pins 248 and 250. The triangular orwedged-shaped implant can be urged laterally between and thus distractthe upper and lower spinous processes. Once the appropriate distractionis reached, pins 248, 250 can be inserted through the appropriate boresof the bore pluralities 245 and 246 in order to lock the spinousprocesses in a V-shaped valley formed by pins 248, 250 on the one handand the ramped surface 233, 235 on the other hand.

Turning to FIG. 38, the implant 234 has a triangular-shaped orwedge-shaped body similar to that shown in FIG. 32. In this embodiment;tab 252, 254 are pivotally mounted to the triangular shaped body 234.Once the implant 234 is appropriately positioned in order to distractthe spinous processes to the desired amount, the tabs 252, 254 rotateinto position in order to hold the implant 234 in the appropriateposition.

Embodiments of FIGS. 39 and 40

In the embodiment of FIGS. 39 and 40, cannula 258 is inserted through asmall incision to a position between upper and lower spinous processes.Once the cannula is properly inserted, an implant 260 is pushed throughthe cannula 258 using an insertion tool 262. The implant 260 includes aplurality of ribs or indentation 264 that assist in positioning theimplant 260 relative to the upper and lower spinal processes. Once theimplant 260 is in position, the cannula 258 is withdrawn so that theimplant 260 comes in contact with and wedges between the spinousprocesses. The cannula 258 is somewhat conical in shape with the noseend 266 being somewhat smaller than the distal end 268 in order toeffect the insertion of the cannula into the space between the spinousprocesses.

Further, a plurality of cannula can be used instead of one, with eachcannula being slightly bigger than one before. In the method of theinvention, the first smaller cannula would be inserted followed bysuccessively larger cannula being placed over the previous smallercannula. The smaller cannula would then be withdrawn from the center ofthe larger cannula. Once the largest cannula is in place, and theopening of the skin accordingly expanded, the implant, which isaccommodated by only the larger cannula, is inserted through the largercannula and into position.

Embodiments of FIGS. 41, 42 and 43

The precurved implant 270 in FIGS. 41 and 42, and precurved implant 272in FIG. 43 have common introduction techniques which includes a guidewire, guide tool, or stylet 274. For both embodiments, the guide wire274 is appropriately positioned through the skin of the patient and intothe space between the spinous processes. After this is accomplished, theimplant is directed over the guide wire and into position between thespinous processes. The precurved nature of the implant assist in (1)positioning the implant through a first small incision in the patient'sskin on one side of the space between two spinous processes and (2)guiding the implant toward a second small incision in the patient's skinon the other side of the space between the two spinous processes. Withrespect to the implant 270, the implant includes a conical introductionnose 276 and a distal portion 278. As the nose 276 is inserted betweenthe spinous processes, this causes distraction of the spinous processes.Break lines 280, 282 are established at opposite sides of the implant270. Once the implant is properly positioned over the guide wire betweenthe spinous processes, the nose portion 276 and the distal portion 278can be broken off along the break lines, through the above twoincisions, in order to leave the implant 270 in position.

Although only two break lines 280, 282 are depicted, multiple breaklines can be provided on implant 270 so that the implant can continue tobe fed over the guide wire 278 until the appropriate width of theimplant 270 creates the desired amount of distraction. As describedhereinabove, the break lines can be created by perforating or otherwiseweakening the implant 270 so that the appropriate portions can besnapped or sawed off.

With respect to the precurved implant 272, this implant is similar indesign to the implant 230 shown in FIG. 36. This implant 272 in FIG. 47,however, is precurved and inserted over a guide wire 274 to a positionbetween the spinous processes. As with implant 230 in FIG. 43, once theappropriate level of this distraction has been reached and if desired,sections of the implant 272 can be broken, snapped or sawed off asdescribed hereinabove in order to leave a portion of the implant wedgedbetween the upper and lower spinous processes.

Embodiment of FIG. 44

A further embodiment of the invention is shown in FIG. 44. Thisembodiment includes a combination insertion tool and implant 290. Theinsertion tool and implant 290 is in the shape of a ring which is hingedat point 292. The ring is formed by a first elongated and conicallyshaped member 294 and a second elongated and conically shaped member296. Members 294 and 296 terminate in points and through the use ofhinge 292 are aligned and meet. Through similar incisions on both sidesof the spinous processes, first member and second member are insertedthrough the skins of the patient and are mated together between thespinous processes. After this has occurred, the implant 290 is rotated,for example clockwise, so that increasingly widening portions of thefirst member 292 are used to distract the first and second spinousprocesses. When the appropriate level of distraction has occurred, theremainder of the ring before and after the section which is locatedbetween the spinous processes can be broken off as taught hereinabove inorder to maintain the desired distraction. Alternatively, with a smallenough ring, the entire ring can be left in place with the spinousprocesses distracted.

Embodiment of FIG. 45

In FIG. 45, the implant 300 is comprised of a plurality of rods orstylets 302 which are inserted between the upper and lower spinousprocesses. The rods are designed much as described hereinabove so thatthey may be broken, snapped or cut off. Once these are inserted and theappropriate distraction has been reached, the stylets are broken off anda segment of each stylet remains in order to maintain distraction of thespinous process.

Embodiments of FIGS. 46 and 47

Implant 310 of FIGS. 46 and 47 is comprised of a shape memory materialwhich coils upon being released. The material is straightened out in adelivery tool 312. The delivery tool is in position between upper andlower spinous processes 314, 316. The material is then pushed throughthe delivery tool. As it is released from the delivery end 318 of thedelivery tool, the material coils, distracting the spinous processes tothe desired amount. Once this distraction has been achieved, thematerial is cut and the delivery tool removed.

Embodiments of FIGS. 48, 49, 50 and 51

As can be seen in FIG. 48, the implant 320 is delivered between upperand lower spinous processes 322 and 324, by delivery tool 326. Once theimplant 320 is in place between the spinous processes, the delivery toolis given a 90° twist so that the implant goes from the orientation asshown in FIG. 49, with longest dimension substantially perpendicular tothe spinous processes, to the orientation shown in FIG. 50 where thelongest dimension is in line with and parallel to the spinous processes.This rotation causes the desired distraction between the spinousprocesses. Implant 320 includes opposed recesses 321 and 323 located atthe ends thereof. Rotation of the implant 320 causes the spinousprocesses to become lodged in these recesses.

Alternatively, the insertion tool 326 can be used to insert multipleimplants 320, 321 into the space between the spinous processes 322, 324(FIG. 51). Multiple implants 320, 321 can be inserted until theappropriate amount of distraction is built up. It is to be understood inthis situation that one implant would lock to another implant by use of,for example, a channel arrangement wherein a projection from one of theimplants would be received into and locked into a channel of the otherimplant. Such a channel arrangement is depicted with respect to theother embodiment.

Embodiments of FIGS. 52, 53, 54, 55 a and 55 b

The embodiment of FIGS. 52 through 55 b is comprised of a fluid-filleddynamic distraction implant 350. This implant includes a membrane 352which is placed over pre-bent insertion rod 354 and then insertedthrough an incision on one side of the spinous process 356. The bentinsertion rod, with the implant 350 thereover, is guided betweenappropriate spinous processes. After this occurs, the insertion rod 354is removed leaving the flexible implant in place. The implant 350 isthen connected to a source of fluid (gas, liquid, gel and the like) andthe fluid is forced into the implant causing it to expand as shown inFIG. 54, distracting the spinal processes to the desired amount. Oncethe desired amount of distraction has occurred, the implant 350 isclosed off as is shown in FIG. 55 a. The implant 350 being flexible, canmold to the spinous processes which may be of irregular shape, thusassuring positioning. Further, implant 350 acts as a shock absorber,damping forces and stresses between the implant and the spinousprocesses.

A variety of materials can be used to make the implant and the fluidwhich is forced into the implant. By way of example only, viscoelasticsubstances such as methylcellulose, or hyaluronic acid can be used tofill the implant. Further, materials which are initially a fluid, butlater solidify, can be inserted in order to cause the necessarydistraction. As the materials solidify, they mold into a custom shapeabout the spinous processes and accordingly are held in position atleast with respect to one of two adjacent spinous processes. Thus, itcan be appreciated that using this embodiment and appropriate insertiontools the implant can be formed about one spinous process in such amanner that the implant stays positioned with respect to that spinousprocess (FIG. 55 b). With such an embodiment, a single implant can beused as an extension stop for spinous process located on either side,without restricting flexion of the spinal column.

It is to be understood that many of the other implants disclosed hereincan be modified so that they receive a fluid in order to establish andmaintain a desired distraction much in the manner as implant 350receives a fluid.

Embodiments of FIGS. 56, 57 and 58

The implant 360 as shown in FIG. 56 is comprised of a shape memorymaterial such as a plastic or a metal. A curved introductory tool 362 ispositioned between the appropriate spinous processes as describedhereinabove. Once this has occurred, bore 364 of the implant is receivedover the tool. This act can cause the implant to straighten out. Theimplant is then urged into position and thereby distracts the spinousprocesses. When this has occurred, the insertion tool 362 is removed,allowing the implant to assume its pre-straightened configuration and isthereby secured about one of the spinous processes. Such an arrangementallows for an implant that is an extension stop and does not inhibitflexion of the spinous column. Alternatively, the implant can betemperature sensitive. That is to say that the implant would be morestraightened initially, but become more curved when it was warmed by thetemperature of the patient's body.

Embodiments of FIGS. 59 and 60

In this embodiment, the implant 380 is comprised of a plurality ofinterlocking leaves 382. Initially, a first leaf is positioned betweenopposed spinous processes 384, 386. Then subsequently, leafs 382 areinterposed between the spinous processes until the desired distractionhas been built up. The leaves are somewhat spring-like in order toabsorb the shock and can somewhat conform to the spinous processes.

Embodiment of FIG. 61

The implant 390 of FIG. 61 includes the placement of shields 392, 394over adjacent spinous processes 396, 398. The shields are used toprevent damage to the spinous processes. These shields include apertureswhich receives a self-tapping screw 400, 402. In practice, the shieldsare affixed to the spinous processes and the spinous processes aredistracted in the appropriate amount. Once this has occurred, a rod 404is used to hold the distracted position by being screwed into each ofthe spinous processes through the aperture in the shields using thescrews as depicted in FIG. 61.

Embodiments of FIGS. 62 and 63

Implant 410 of FIGS. 62, 63 is comprised of first and second members412, 414 which can be mated together using an appropriate screw andthreaded bore arrangement to form the implant 410. Main member 412 andmating member 414 form implant 410. Accordingly, the implant 410 wouldhave a plurality of members 414 for use with a standardized first member412. FIGS. 62 and 64 show different types of mating members 414. In FIG.62, the mating member 414 includes projections 416 and 418 which actlike shims. These projections are used to project into the space ofsaddles 420, 422 of the first member 412. These projections 416, 418 canbe of varying lengths in order to accommodate different sizes of spinousprocesses. A groove 424 is placed between the projections 416, 418 andmates with an extension 426 of the first member 412.

As shown in FIG. 63, the projections of the embodiment shown in FIG. 62are removed and recesses 428, 430 are substituted therefor. Theserecesses expand the area of the saddles 420, 422 in order to accommodatelarger spinous processes.

Embodiments of FIGS. 64, 65 and 66

The embodiments of FIGS. 64, 65 and 66 are similar in design and conceptto the embodiment of FIGS. 62 and 63. In FIG. 64, the implant 500includes the first and second members 502, 504. These members can besecured together with appropriate screws or other fastening means astaught in other embodiments. Implant 500 includes first and secondsaddles 506, 508 which are formed between the ends of first and secondmembers 502, 504. These saddles 506, 508 are used to receive and cradlethe adjacent spinous processes. As can be seen in FIG. 64, each saddle506, 508 is defined by a single projection or leg 510, 512, whichextends from the appropriate first and second members 502, 504. Unlikethe embodiment found in FIGS. 62 and 63, each of the saddles is definedby only a single leg as the ligaments and other tissues associated withthe spinous processes can be used to ensure that the implant is held inan appropriate position. With the configuration of FIG. 64, it is easierto position the implant relative to the spinous processes as each saddleis defined by only a single leg and thus the first and second memberscan be more easily worked into position between the various tissues.

In the embodiment of FIG. 65, the implant 520 is comprised of a singlepiece having saddles 522 and 524. The saddles are defined by a singleleg 526, 528 respectively. In order for this implant 520 to bepositioned between the spinous processes, an incision is made betweenlateral sides of adjacent spinous processes. The single leg 526 isdirected through the incision to a position adjacent to an oppositelateral side of the spinous process with the spinous process cradled inthe saddle 522. The spinous processes are then urged apart until saddle524 can be pivoted into position into engagement with the other spinousprocess in order to maintain the distraction between the two adjacentspinous processes.

The embodiment of FIG. 66 is similar to that of FIG. 65 with an implant530 and first and second saddles 532 and 534. Associated with eachsaddle is a tether 536, 538 respectively. The tethers are made offlexible materials known in the trade and industry and are positionedthrough bores in the implant 530. Once appropriately positioned, thetethers can be tied off. It is to be understood that the tethers are notmeant to be used to immobilize one spinous process relative to theother, but are used to guide motion of the spinous processes relative toeach other so that the implant 530 can be used as an extension stop anda flexion non-inhibitor. In other words, the saddles 532, 534 are usedto stop spinal column backward bending and extension. However, thetethers do not inhibit forward bending and spinal column flexion.

Embodiments of FIGS. 67, 68

The implant 550 is Z-shaped and includes a central body 552 and firstand second arms 554, 556, extending in opposite directions therefrom.The central body 552 of the implant 550 includes first and secondsaddles 558 and 560. The first and second saddles 558 and 560 wouldreceive upper and lower spinous processes 562, 568. The arms 554, 556are accordingly located adjacent the distal end 566 (FIG. 68) of thecentral body 552. The first and second arms 554, 556, act to inhibitforward movement, migration or slippage of the implant 550 toward thespinal canal and keep the implant in place relative to the first andsecond spinal processes. This prevents the implant from pressing down onthe ligamentum flavum and the dura. In a preferred embodiment, thecentral body would have a height of about 10 mm with each of the arms554, 556 have a height of also about 10 mm. Depending on the patient,the height of the body could vary from about less than 10 mm to aboutgreater than 24 mm. As can be seen in FIGS. 67 and 68, the first andsecond arms 554, 556 are additionally contoured in order to accept theupper and lower spinous processes 556, 558. In particular, the arms 554,556 as can be seen with respect to arm 554 have a slightly outwardlybowed portion 568 (FIG. 68) with a distal end 570 which is slightlyinwardly bowed. This configuration allows the arm to fit about thespinous process with the distal end 570 somewhat urged against thespinous process in order to guide the motion of the spinous processrelative to the implant. These arms 554, 556 could if desired to be mademore flexible than the central body 552 by making arms 554, 556 thinand/or with perforations, and/or other material different than that ofthe central body 550. As with the last embodiment, this embodiment canbe urged into position between adjacent spinous processes by directingan arm into a lateral incision so that the central body 552 can befinally positioned between spinous processes.

Embodiments of FIGS. 69, 70, 71 and 71 a

FIGS. 69, 70 and 71 are perspective front, end, and side views ofimplant 580 of the invention. This implant includes a central body 582which has first and second saddles 584, 586 for receiving adjacentspinous processes. Additionally, the implant 580 includes first andsecond arms 588 and 590. The arms, as with the past embodiment, preventforward migration or slippage of the implant toward the spinal canal.First arm 588 projects outwardly from the first saddle 584 and secondarm 590 projects outwardly from the second saddle 586. In a preferredembodiment, the first arm 588 is located adjacent to the distal end 600of the central body 582 and proceeds only partly along the length of thecentral body 582. The first arm 588 is substantially perpendicular tothe central body as shown in FIG. 70. Further, the first arm 588, aswell as the second arm 590, is anatomically rounded.

The second arm 590, projecting from second saddle 586, is locatedsomewhat rearward of the distal end 600, and extends partially along thelength of the central body 582. The second arm 590 projects at acompound angle from the central body 582. As can be seen in FIGS. 70 and71, the second arm 590 is shown to be at about an angle of 45° from thesaddle 586 (FIG. 70). Additionally, the second arm 590 is at an angle ofabout 45° relative to the length of the central body 580 as shown inFIG. 71. It is to be understood that other compound angles are withinthe spirit and scope of the invention as claimed.

In a preferred embodiment, the first and second arms 588, 590 have alength which is about the same as the width of the central body 582.Preferably, the length of each arm is about 10 mm and the width of thecentral body is about 10 mm. However, the bodies with the widths of 24mm and greater are within the spirit and scope of the invention, alongwith first and second arms ranging from about 10 mm to greater thanabout 24 mm. Further, it is contemplated that the embodiment couldinclude a central body having a width of about or greater than 24 mmwith arms being at about 10 mm.

It is to be understood that the embodiment of FIGS. 69, 70 and 71 aswell as the embodiment of FIGS. 67 and 68 are designed to preferably bepositioned between the L4-L5 and the L5-S1 vertebral pairs. Theembodiment of FIGS. 69, 70, 71 is particularly designed for the L5-S1position with the arms being designed to conform to the sloping surfacesfound therebetween. The first and second arms are thus contoured so thatthey lie flat against the lamina of the vertebra which has a slightangle.

The embodiment of FIGS. 69, 70, and 71 as with the embodiment of FIGS.67 and 68 is Z-shaped in configuration so that it may be inserted fromone lateral side to a position between adjacent spinous processes. Afirst arm, followed by the central body, is guided through the spacebetween the spinous processes. Such an arrangement only requires that aincision on one side of the spinous process be made in order tosuccessfully implant the device between the two spinous processes.

The implant 610 of FIG. 71 a is similar to that immediately above withthe first arm 612 located on the same side of the implant as the secondarm 614. The first and second saddle 616, 618 are slightly modified inthat distal portion 620, 622 are somewhat flattened from the normalsaddle shape in order to allow the implant to be positioned between thespinous processes from one side. Once in position, the ligaments andtissues associated with the spinous processes would hold the implantinto position. Tethers also could be used if desired.

Embodiments of FIGS. 72, 73

Implant 630 is also designed so that it can be inserted from one side ofadjacent spinous processes. This insert 630 includes a central body 632with the first and second arms 634, 636 extending on either sidethereof. As can be seen in FIG. 72, a plunger 638 is positioned toextend from an end of the central body 632. As shown in FIG. 72, theplunger 638 is fully extended and as shown in FIG. 73, the plunger 638is received within the central body 632 of the implant 630. With theplunger received into the implant 632, the third and fourth arms orhooks 640, 642 can extend outwardly from the central body 632. The thirdand fourth arms or hooks 640, 642 can be comprised of a variety ofmaterials, such as for example, shape memory metal materials ormaterials which have a springy quality.

For purposes of positioning the implant 630 between adjacent spinousprocesses, the plunger 638 is pulled outwardly as shown in FIG. 72. Thecentral body 632 is then positioned between adjacent spinous processesand the plunger 638 is allowed to move to the position of FIG. 73 sothat the third and fourth arms 640, 642 can project outwardly from thecentral body 632 in order to hold the implant 630 in position betweenthe spinous processes.

Plunger 638 can be spring biased to the position as shown in FIG. 73 orcan include detents or other mechanisms which lock it into thatposition. Further, the third and fourth arms themselves, as deployed,can keep the plunger in the position as shown in FIG. 73.

Embodiments of FIGS. 74, 75, 76, 77, and 78

Other embodiments of the invention are shown in FIGS. 74 through 78.FIGS. 74, 75 and 76 disclose implant 700. Implant 700 is particularlysuited for implantation between the L4-L5 and L5-S1 vertebra. As can beseen in FIG. 74, the implant 700 includes a central body 702 which has abore 704 provided therein. Bore 704 is used in order to adjust themodulus of elasticity of the implant so that it is preferablyapproximately two times the anatomical load placed on the vertebra inextension. In other words, the implant 700 is approximately two timesstiffer than the normal load placed on the implant. Such an arrangementis made in order to ensure that the implant is somewhat flexible inorder to reduce potential resorption of the bone adjacent to theimplant. Other modulus values can be used and be within the spirit ofthe invention.

Implant 700 includes first and second saddle 706, 708 which are used toreceive and spread the load from the upper and lower spinous processes.The saddle 706 is defined by first and second arms 710 and 712. Thesecond saddle 708 is defined by third and fourth arms 714 and 716. Ascan be seen in FIG. 74, the first arm 710, in a preferred embodiment, isapproximately two times the length of the body 702 with the second armbeing approximately less than a quarter length of the body. Third arm714 is approximately one times the length of the body 702 with thefourth arm 716 being, in this preferred embodiment, approximately oneand a half times the length of the body 702. The arms are designed insuch a way that the implant (1) can be easily and conveniently insertedbetween the adjacent spinous processes, (2) will not migrate forwardlytoward the spinal canal, and (3) will hold its position through flexionand extension as well as lateral bending of the spinal column.

First arm 710 is in addition designed to accommodate the shape of thevertebra. As can be seen in FIG. 74, the first arm 710 becomes narroweras it extends away from the body 702. The first arm 710 includes asloping portion 718 followed by a small recess 720 ending in a roundedportion 722 adjacent to the end 724. This design is provided toaccommodate the anatomical form of for example the L4 vertebra. It is tobe understood that these vertebra have a number of surfaces at roughly30° angles and that the sloping surfaces of this embodiment and theembodiments shown in FIGS. 77 and 78 are designed to accommodate thesesurfaces. These embodiments can be further modified in order toaccommodate other angles and shapes.

The second arm 712 is small so that it is easy to insert between thespinous processes, yet still define the saddle 706. The fourth arm 716is larger than the third arm 714, both of which are smaller than thefirst arm 710. The third and fourth arms are designed so that theydefine the saddle 706, guide the spinous processes relative to theimplant 700 during movement of the spinal column, and yet are of a sizewhich makes the implant easy to position between the spinous processes.

The procedure, by way of example only, for implanting the implant 700can be to make an incision laterally between two spinous processes andthen initially insert first arm 710 between the spinous processes. Theimplant and/or appropriate tools would be used to distract the spinousprocesses allowing the third leg 714 and the central body 702 to fitthrough the space between the spinous processes. The third leg 714 wouldthen come to rest adjacent the lower spinous processes on the oppositeside with the spinous processes resting in the first and second saddle706, 708. The longer fourth leg 716 would then assist in the positioningof the implant 700.

FIG. 77 includes an implant 740 which is similar to implant 700 and thushave similar numbering. The saddle 706, 708 of implant 740 have beencantered or sloped in order to accommodate the bone structure between,by way of example, the L4-L5 and the L5-S1 vertebra. As indicated above,the vertebra in this area have a number of sloping surfaces in the rangeof about 30°. Accordingly, saddle 706 is sloped at less than 30° andpreferably about 20° while saddle 708 is sloped at about 30° andpreferably more than 30°.

The implant 760 as shown in FIG. 78 is similar to implant 700 in FIG. 74and is similarly numbered. Implant 760 includes third and fourth legs714, 716 which have sloping portions 762, 764 which slope toward ends766, 768 of third and fourth arm 714, 716 respectively. The slopingportions accommodate the form of the lower vertebra against which theyare positioned. In the preferred embodiment, the sloping portions are ofabout 30°. However, it is to be understood that sloping portions whichare substantially greater and substantially less than 30° can beincluded and be within the spirit and scope of the invention.

Embodiments of FIGS. 79, 80, 80 a, 81, 82, 83, 83 a, 84, 85, 86 and 87

Another embodiment of the invention is shown in FIGS. 79-87 and includesimplant 800 (FIG. 86). Implant 800 includes a distracting unit 802 whichis shown in left side, plan, and right side views of FIGS. 79, 80 and81. A perspective view of the distraction unit is shown in FIG. 84. Thedistracting unit as can be seen in FIG. 80 includes a distracting body804, with longitudinal axis 805, which body 804 has a groove 806 and arounded or bulbous end 808 which assist in the placement of thedistracting body between adjacent spinous process so that an appropriateamount of distraction can be accomplished. Extending from thedistracting body 804 is a first wing 810 which in FIG. 80 issubstantially perpendicular to the distracting body 804. Such wingswhich are not perpendicular to the body are within the spirit and scopeof the invention. First wing 810 includes a upper portion 812 and alower portion 814. The upper portion 810 (FIGS. 79) includes a roundedend 816 and a small recess 818. The rounded end 816 and the small recess818 in the preferred embodiment are designed to accommodate theanatomical form or contour of the L4 (for a L4-L5 placement) or L5 (fora L5-S1 placement) superior lamina of the vertebra. It is to beunderstood that the same shape or variations of this shape can be usedto accommodate other lamina of any vertebra. The lower portion 814 isalso rounded in order to accommodate in the preferred embodiment inorder to accommodate the vertebrae. The distracting unit furtherincludes a threaded bore 820 which in this embodiment accepts a setscrew 822 (FIG. 86) in order to hold a second wing 824 (FIGS. 82, 83) inposition as will be discussed hereinbelow.

The threaded bore 820 in this embodiment slopes at approximately 45°angle and intersects the slot 806. With the second wing 824 in position,the set screw 822 when it is positioned in the threaded bore 820 canengage and hold the second wing 824 in position in the slot 806.

Turning to FIGS. 82, 83 and 85, left side, plan and perspective views ofthe second wing 824 are depicted. The second wing 824 is similar indesign to the first wing. The second wing includes an upper portion 826and a lower portion 828. The upper portion includes a rounded end 830and a small recess 832. In addition, the second wing 824 includes a slot834 which mates with the slot 806 of the distracting unit 802. Thesecond wing 824 is the retaining unit of the present embodiment.

As can be seen in FIGS. 83 and 86, the second wing or retaining unit 824includes the upper portion 826 having a first width “a” and the lowerportion 828 having a second width “b”. In the preferred embodiment, thesecond width “b” is larger than first width “a” due to the anatomicalform or contour of the L4-L5 or L5-S1 laminae. As can be seen in FIG. 83a in second wing or retaining unit 824, the widths “a” and “b” would beincreased in order to, as described hereinbelow, accommodate spinousprocesses and other anatomical forms or contours which are of differentdimensions. Further, as appropriate, width “a” can be larger than width“b”. Thus, as will be described more fully hereinbelow, the implant caninclude a universally-shaped distracting unit 802 with a plurality ofretaining units 824, with each of the retaining units having differentwidths “a” and “b”. During surgery, the appropriately sized retainingunit 824, width with the appropriate dimensions “a” and “b” can beselected to match to the anatomical form of the patient.

FIG. 86 depicts an assembled implant 800 positioned adjacent to upperand lower laminae 836, 838 (which are shown in dotted lines) of theupper and lower vertebrae. The vertebrae 836, 838 are essentially belowthe implant 800 as shown in FIG. 86. Extending upwardly from thevertebrae 836, 838, and between the first and second wings 810, 824, arethe upper and lower spinous processes 840, 842. It is to be understoodthat in a preferred embodiment, the fit of the implant between thespinous processes can be such that the wings do not touch the spinousprocesses, as shown in FIG. 86, and be within the spirit and scope ofthe invention.

The implant 800 includes, as assembled, an upper saddle 844 and thelower saddle 846. The upper saddle 844 has an upper width identified bythe dimension “UW”. The lower saddle 846 has a lower width identified bythe dimension “LW”. In a preferred embodiment, the upper width isgreater than the lower width. In other embodiments, the “UW” can besmaller than the “LW” depending on the anatomical requirements. Theheight between the upper and lower saddles 844, 846 is identified by theletter “h”. These dimensions are carried over into FIG. 87 which is aschematic representation of the substantially trapezoidal shape which isformed between the upper and lower saddles. The table below gives setsof dimensions for the upper width, lower width, and height as shown inFIG. 87. This table includes dimensions for some variations of thisembodiment.

TABLE Variation 1 2 3 Upper Width 8 7 6 Lower Width 7 6 5 Height 10 9 8For the above table, all dimensions are given in millimeters.

For purposes of surgical implantation of the implant 800 into a patient,the patient is preferably positioned on his side (arrow 841 points upfrom an operating table) and placed in a flexed (tucked) position inorder to distract the upper and lower vertebrae.

In a preferred procedure, a small incision is made on the midline of thespinous processes. The spinous processes are spread apart or distractedwith a spreader. The incision is spread downwardly toward the table, andthe distracting unit 802 is preferably inserted upwardly between thespinous processes 840 and 842 in a manner that maintains the distractionof spinous processes. The distracting unit 802 is urged upwardly untilthe distracting or bulbous end 808 and the slot 806 are visible on theother wide of the spinous process. Once this is visible, the incision isspread upwardly away from the table and the retaining unit or secondwing 824 is inserted into the slot 806 and the screw 822 is used tosecure the second wing in position. After this had occurred, theincisions can be closed.

An alternative surgical approach requires that small incisions be madeon either side of the space located between the spinous processes. Thespinous processes are spread apart or distracted using a spreader placedthrough the upper incision. From the lower incision, the distractingunit 802 is preferably inserted upwardly between the spinous processes840 and 842 in a manner that urges the spinous processes apart. Thedistracting unit 802 is urged upwardly until the distracting or bulbousend 808 and the slot 806 are visible through the second small incisionin the patient's back. Once this is visible, the retaining unit orsecond wing 824 is inserted into the slot 806 and the screw 822 is usedto secure the second wing in position. After this has occurred, theincisions can be closed.

The advantage of either of the above present surgical procedures is thata surgeon is able to observe the entire operation, where he can lookdirectly down onto the spinous processes as opposed to having to viewthe procedure from positions which are to the right and to the left ofthe spinous processes. Generally, the incision is as small as possibleand the surgeon is working in a bloody and slippery environment. Thus,an implant that can be positioned directly in front of a surgeon iseasier to insert and assemble than an implant which requires the surgeonto shift from side to side. Accordingly, a top-down approach, as anapproach along a position to anterior line is preferred so that allaspects of the implantation procedure are fully visible to the surgeonat all times. This aides in the efficient location of (i) thedistracting unit between the spinous processes, (ii) the retaining unitin the distracting unit, and (iii) finally the set screw in thedistracting unit.

FIG. 80 a shows an alternative embodiment of the distracting unit 802 a.This distracting unit 802 a is similar to distracting unit 802 in FIG.80 with the exception that the bulbous end 808 a is removable from therest of the distracting body 804 a as it is screwed into the threadedbore 809. The bulbous end 808 a is removed once the distracting unit 802a is positioned in the patient in accordance with the descriptionassociated with FIG. 86. The bulbous end 808 a can extend past thethreaded bore 820 by about 1 cm in a preferred embodiment.

Embodiments of FIGS. 88, 89, 90 and 91

Another embodiment of the invention is shown in FIGS. 88, 89, 90 and 91.In this embodiment, the implant is identified by the number 900. Otherelements of implant 900 which are similar to implant 800 are similarlynumbered but in the 900 series. For example, the distracting unit isidentified by the number 902 and this is in parallel with thedistracting unit 802 of the implant 800. The distracting body isidentified by the number 904 in parallel with the distracting body 804of the implant 800. Focusing on FIG. 90, the distracting unit 902 isdepicted in a perspective view. The distracting unit includes slot 906which is wider at the top than at the bottom. The reason for this isthat the wider upper portion of the slot 906, which is wider than thesecond wing 924 (FIG. 89), is used to allow the surgeon to easily placethe second wing 924 into the slot 906 and allow the wedge-shaped slot906 to guide the second wing 924 to its final resting position. As canbe see in FIG. 91, in the final resting position, the largest portion ofthe slot 906 is not completely filled by the second wing 924.

The end 908 of implant 900 is different in that it is more pointed,having sides 909 and 911 which are provided at about 45° angles (otherangles, such as by way of example only, from about 30° to about 60° arewithin the spirit of the invention), with a small flat tip 913 so thatthe body 904 can be more easily urged between the spinous processes.

The distracting unit 902 further includes a tongue-shaped recess 919which extends from the slot 906. Located in the tongue-shaped recess isa threaded bore 920.

As can be seen in FIG. 89, a second wing 924 includes a tongue 948 whichextends substantially perpendicular thereto and between the upper andlower portions 926, 928. The tab 948 includes a bore 950. With thesecond wing 924 positioned in the slot 906 of the distracting unit 902and tab 948 positioned in recess 919, a threaded set screw 922 can bepositioned through the bore 950 and engage the threaded bore 920 inorder to secure the second wing or retaining unit 924 to the distractingunit 902. The embodiment 900 is implanted in the same manner asembodiment 800 previously described. In addition, as the bore 922 issubstantially perpendicular to the distracting body 904 (and notprovided at an acute angle thereto), the surgeon can even more easilysecure the screw in place from a position directly behind the spinousprocesses.

Embodiments of FIGS. 92, 92 a, 92 b, 93, 93 a, 93 b, 93 c, 93 d, 94, 94a, 94 b, 95, 95 a, and 96

Still a further embodiment of the invention is depicted in FIGS. 92, and92 a. In this embodiment, the implant 1000 as can be seen in FIG. 92 aincludes a central elongated body 1002 which has positioned at one endthereof a first wing 1004. Wing 1004 is similar to the first wingpreviously described with respect to the embodiment of FIG. 88. Bolt1006 secures wing 1004 to body 1002 in this embodiment. Bolt 1006 isreceived in a bore of the body 1002 which is along the longitudinal axis1008 of body. It is to be understood that in this embodiment, the firstunit is defined by the central body 1002, the first wing 1004, and theguide 1010.

Alternatively, the first wing can be secured to the central body with apress fit and detent arrangement as seen in FIG. 93 c. In thisarrangement, the first wing has a protrusion 1040 extending preferablyabout perpendicularly from the first wing, with a flexible catch 1042.The protrusion and flexible catch are press fit into a bore 1044 of thecentral body with the catch received in a detent 1046.

In yet another alternative embodiment, the first wing can be designed asshown in FIG. 93 d with the protrusion directed substantially parallelto the first wing from a member that joins the first wing to theprotrusion. Thus in this embodiment, the first wing is inserted into thebody along the same direction as the second wing is inserted.

Positioned at the other end of the central body 1002 is a guide 1010. Inthis particular embodiment, guide 1010 is essentiallytriangularly-shaped so as to be a pointed and arrow-shaped guide.Alternatively, guide 1010 could be in the shape of a cone with lateraltruncated sides along the longitudinal axis 1008. Guide 1010 includes arecess 1012 having a threaded bore 1014. Recess 1012 is for receiving asecond wing 1032 as will be described hereinbelow.

Additionally, it is also to be understood that the guide 1010 can bebulbous, cone-shaped, pointed, arrow-shaped, and the like, in order toassist in the insertion of the implant 1000 between adjacent spinousprocesses. It is advantageous that the insertion technique disturb aslittle of the bone and surrounding tissue or ligaments as possible inorder to (1) reduce trauma to the site and facilitate early healing, and(2) not destabilize the normal anatomy. It is to be noted that with thepresent embodiment, there is no requirement to remove any of the bone ofthe spinous processes and depending on the anatomy of the patient, theremay be no requirement to remove or sever ligaments and tissuesimmediately associated with the spinous processes.

The implant 1000 further includes a sleeve 1016 which fits around and isat least partially spaced from the central body 1002. As will beexplained in greater detail below, while the implant may be comprised ofa bio-compatible material such as titanium, the sleeve is comprisedpreferably of a super-elastic material which is by way of example only,a nickel titanium material (NiTi), which has properties which allow itto withstand repeated deflection without fatigue, while returning to itsoriginal shape. The sleeve could be made of other materials, such as forexample titanium, but these materials do not have the advantages of asuper-elastic material.

FIG. 93 a is a cross-section through the implant 1000 depicting thecentral body 1002 and the sleeve 1016. As can be seen from thecross-section of FIG. 93 a in a preferred embodiment, both the centralbody 1002 and the sleeve 1016 are substantially cylindrical and oval orelliptically-shaped. An oval or elliptical shape allows more of thespinous process to be supported by the sleeve, thereby distributing theload between the bone and the sleeve more evenly. This reduces thepossibility of fracture to the bone or bone resorption. Additionally, anoval or elliptical shape enhances the flexibility of the sleeve as themajor axis of the sleeve, as described below, is parallel to thelongitudinal direction of the spinous process. However, other shapessuch as round cross-sections can come within the spirit and scope of theinvention.

In this particular embodiment, the central body 1002 includes elongatedgrooves 1018, along axis 1008, which receives elongated spokes 1020extending from the internal surface of the cylinder 1016.

In a preferred embodiment, both the cross-section of the central bodyand the sleeve have a major dimension along axis 1022 and a minordimensional along axis 1024 (FIG. 93 a). The spokes 1020 are along themajor dimension so that along the minor dimension, the sleeve 1016 canhave its maximum inflection relative to the central body 1002. It is tobe understood that the central body along the minor dimension 1024 canhave multiple sizes and can, for example, be reduced in thickness inorder to increase the ability of the sleeve 1016 to be deflected in thedirection of the central body 1002.

Alternatively as can be seen in FIG. 93 b, the central body 1002 caninclude the spokes 1020 and the sleeve 1016 can be designed to includethe grooves 1018 in order to appropriately space the sleeve 1016 fromthe central body 1002.

In other embodiments, the sleeve can have minor and major dimensions asfollows:

Minor Dimension Major Dimension 6 mm 10 mm 8 mm 10.75 mm 12 mm 14 mm 6mm 12.5 mm 8 mm 12.5 mm 10 mm 12.5 mm

In one preferred embodiment, said sleeve has a cross-section with amajor dimension and a minor dimension and said major dimension isgreater than said minor dimension and less than about two times saidminor dimension. In said embodiment, said guide has a cross-sectionwhich is adjacent to said sleeve with a guide major dimension aboutequal to said sleeve major dimension and a guide minor dimension aboutequal to said sleeve minor dimension. Further in said embodiment, saidguide extends from said central body with a cross-section which reducesin size in a direction away from said central body.

In another preferred embodiment, said guide is cone-shaped with a baselocated adjacent to said sleeve. Further, said guide has a basecross-section about the same as the oval cross-section of said sleeve.

Thus, from the above, it is evident that preferably a major dimension ofthe sleeve correspond with a major dimension of the central body and aminor dimension of the sleeve corresponds with a minor dimension of thecentral body. Additionally, it is evident that the major dimension ofthe sleeve 1016 is substantially perpendicular to a major dimension ofthe first wing 1004 along longitudinal axis 1030 (FIG. 92 a). This is sothat as discussed above, when the implant 1000 is properly positionedbetween the spinous processes, a major portion of the sleeve comes incontact with both the upper and lower spinous processes in order todistribute the load of the spinous processes on the sleeve 1016 duringspinal column extension.

As indicated above, the preferred material for the sleeve 1016 is asuper-elastic material and more preferably one comprised of an alloy ofnickel and titanium. Such materials are available under the trademarkNitinol. Other super-elastic materials can be used as long as they arebio-compatible and have the same general characteristics ofsuper-elastic materials. In this particular embodiment, a preferredsuper-elastic material is made up of the following composition ofnickel, titanium, carbon, and other materials as follows:

Nickel 55.80% by weight Titanium 44.07% by weight Carbon <0.5% by weightOxygen <0.5% by weight

In particular, this composition of materials is able to absorb about 8%recoverable strain. Of course, other materials which can absorb greaterand less than 8% can come within the spirit and scope of the invention.This material can be repeatably deflected toward the central body andreturned to about its original shape without fatigue. Preferably andadditionally, this material can withstand the threshold stress with onlya small amount of initial deforming strain and above the thresholdstress exhibit substantial and about instantaneous deformation strainwhich is many times the small amount of initial deforming strain. Such acharacteristic is demonstrated in FIG. 118 where it is shown that abovea certain threshold stress level, deformation strain is substantiallyinstantaneous up to about 8%. FIG. 118 shows a loading and unloadingcurve between stress and deformation strain for a typical type ofsuper-elastic material as described above.

Preferably, the above super-elastic material is selected to allowdeformation of up to about, by way of example only, 8%, at about 20 lbs.to 50 lbs. force applied between a spinous processes. This would cause asleeve to deflect toward the central body absorbing a substantial amountof the force of the spinous processes in extension. Ideally, the sleevesare designed to absorb 20 lbs. to 100 lbs. before exhibiting thesuper-elastic effect (threshold stress level) described above. Further,it is possible, depending on the application of the sleeve and theanatomy of the spinal column and the pairs of spinous processes for aparticular individual, that the sleeve can be designed for a preferablerange of 20 lbs. to 500 lbs. of force before the threshold stress levelis reached. Experimental results indicate that with spinous processes ofan older individual, that at about 400 pounds force, the spinous processmay fracture. Further, such experimental results also indicate that withat least 100 pounds force, the spinous process may experience somecompression. Accordingly, ideally the super-elastic material is designedto deform or flex at less than 100 pounds force.

In a preferred embodiment, the wall thickness of the sleeve is about 1mm or 40/1000 of an inch (0.040 in.). Preferably the sleeve is designedto experience a combined 1 mm deflection. The combined 1 mm deflectionmeans that there is ½ mm of deflection at the top of the minor dimensionand a ½ mm deflection at the bottom of the minor dimension. Bothdeflections are toward the central body.

In a particular embodiment where the sleeve is more circular incross-section, with an outer dimension of 0.622 in. and a wall thicknessof 0.034 in., a 20 lb. load causes a 0.005 in. deflection and a 60 lb.load causes a 0.020 in. deflection (approximately ½ mm). A 100 lb. loadwould cause a deflection of about 0.04 in. or approximately 1 mm.

Thus in summary, the above preferred super-elastic material means thatthe sleeve can be repeatedly deflected and returned to about itsoriginal shape without showing fatigue. The sleeve can withstand athreshold stress with a small amount of deforming strain and at aboutsaid threshold stress exhibit about substantially instantaneousdeformation strain which is many times the small amount of the formingstrain. In other words, such super-elastic qualities mean that thematerial experiences a plateau stress where the material supports aconstant force (stress) over very large strain range as exhibited inFIG. 118.

It is to be understood that for this particular embodiment, bar stock ofthe super-elastic material is machined into the appropriate form andthen heat treated to a final temperature to set the shape of thematerial by increasing the temperature of the material to 932°Fahrenheit and holding that temperature for five (5) minutes and thenquickly quenching the sleeve in water. It is also to be understood thatpreferably the present nickel titanium super-elastic alloy is selectedto have a transition temperature A_(f) of about 59° Fahrenheit (15° C.).Generally for such devices the transition temperature can be between 15°C. to 65° C. (59° F. to 149° F.), and more preferably 10° C. to 40° C.(50° F. to 104° F.). Preferably, the material is maintained in the bodyabove the transition temperature in order to exhibit optimal elasticityqualities.

Alternatively, and preferably, the sleeve can be fabricated by wireElectrical Discharge Machining (EDM) rather than machined. Additionally,the sleeve can be finished using a shot blast technique in order toincrease the surface strength and elasticity of the sleeve.

Top and side views of the second wing 1032 are shown in FIGS. 94 and 95.Second wing 1032 as in several past embodiments includes a tab 1034 witha bore 1036 which aligns with the bore 1014 of the guide 1010. In thisparticular embodiment, the second wing 1032 includes a cut-out 1038which is sized to fit over the guide 1010, with the tab 1034 resting inthe recess 1012 of the guide 1010.

An alternative configuration of the second wing 1032 is depicted in FIG.94 a. In this configuration, the second wing 1032 is held at acute anglewith respect to the tab 1034. This is different from the situation inthe embodiment of FIGS. 94 and 95 where the second wing is substantiallyperpendicular to the tab. For the embodiment of the second wing in FIG.94 a, such embodiment will be utilized as appropriate depending on theshape of the spinous processes.

With respect to the alternative second wing 1032 depicted in FIGS. 94 band 95 a, elongated tab 1034 has a plurality of closely positioned bores1036. The bores, so positioned, appear to form a scallop shape. Eachindividual scallop portion of the bore 1036 can selectively hold thebolt in order to effectively position the second wing 1032 in threedifferent positions relative to the first wing 1004. The cut-out 1038(FIG. 95 a of this alternative embodiment) is enlarged over that of FIG.95 as in a position closest to the first wing 1004, the second wing 1032is immediately adjacent and must conform to the shape of the sleeve1016.

Embodiment of FIG. 97

Implant 1050 of FIG. 97 is similar to the implant 1000 in FIG. 92 withthe major difference being that a second wing is not required. Theimplant 1050 includes a central body as does implant 1000. The centralbody is surrounded by a sleeve 1016 which extends between a first wing1004 and a guide 1010. The guide 1010 in this embodiment issubstantially cone-shaped without any flats and with no bore as there isno need to receive a second wing. The sleeve and the central body aswell as the first wing and guide act in a manner similar to those partsof the implant 1000 in FIG. 92. It is to be understood a cross-sectionof this implant 1050 through sleeve 1016 can preferably be like FIG. 93a. This particular embodiment would be utilized in a situation where itwas deemed impractical or unnecessary to use a second wing. Thisembodiment has the significant advantages of the sleeve being comprisedof super-elastic alloy materials as well as the guide being utilized toguide the implant between spinous processes while minimizing damage tothe ligament and tissue structures found around the spinous processes.

Embodiment of FIG. 98

Implant 1060 is depicted in FIG. 98. This implant is similar to theimplants 1000 of FIG. 92 and the implant 1050 of FIG. 97, except thatthis implant does not have either first or second wings. Implant 1060includes a sleeve 1016 which surrounds a central body just as centralbody 1002 of implant 1000 in FIG. 93. It is to be understood that across-section of this implant 1060 through sleeve 1016 can preferably belike FIG. 93 a. Implant 1060 includes a guide 1010 which in thispreferred embodiment is cone-shaped. Guide 1010 is located at one end ofthe central body. At the other end is a stop 1062. Stop 1062 is used tocontain the other end of the sleeve 1016 relative to the central body.This embodiment is held together with a bolt such as bolt 1006 of FIG.93 that is used for the immediate above two implants. For the implant1060 of FIG. 98, such a device would be appropriate where the anatomybetween the spinous processes was such that it would be undesirable touse either a first or second wing. However, this embodiment affords allthe advantageous described hereinabove (FIGS. 92 and 97) with respect tothe guide and also with respect to the dynamics of the sleeve.

Embodiments of FIGS. 99 and 100

FIGS. 99 and 100 depict an implant system 1070. Implant system 1070includes a sleeve 1072 which is similar to and has the advantageous ofsleeve 1016 of the embodiment in FIG. 92. Sleeve 1072 does not, however,have any spokes. Additionally, implant system 1070 includes an insertiontool 1074. Insertion tool 1074 includes a guide 1076 which in apreferred embodiment is substantially cone-shaped. Guide 1076 guides theinsertion of the sleeve 1072 and the insertion tool 1074 betweenadjacent spinous processes. The insertion tool 1074 further includes acentral body 1078, a stop 1080, and a handle 1082. The guide 1076 at itsbase has dimensions which are slightly less than the internal dimensionsof the sleeve 1074 so that the sleeve can fit over the guide 1076 andrest against the stop 1080. The tool 1074 with the guide 1076 is used toseparate tissues and ligaments and to urge the sleeve 1072 in the spacebetween the spinous processes. Once positioned, the guide insertion tool1074 can be removed leaving the sleeve 1072 in place. If desired, afterthe sleeve is positioned, position maintaining mechanisms such asspringy wires 1084 made out of appropriate material such as thesuper-elastic alloys and other materials including titanium, can beinserted using a cannula through the center of the sleeve 1072. Onceinserted, the ends of the retaining wires 1084 (FIG. 99) extend out ofboth ends of the sleeve 1072, and due to this springy nature, bent at anangle with respect to the longitudinal axis of the sleeve 1072. Thesewires help maintain the position of the sleeve relative to the spinousprocesses.

Embodiments of FIGS. 101, 102, 102 a, 103, 104, 105, 106, and 107

Another embodiment of the invention can be seen in FIG. 101 whichincludes implant 1100. Implant 1100 has many similar features that areexhibited with respect to implant 1000 in FIG. 92. Accordingly, elementswith similar features and functions would be similarly numbered.Additionally, features that are different from implant 1100 can be, ifdesired, imported into and become a part of the implant 1000 of FIG. 92.

As with implant 1000, implant 1100 includes a central body 1002 (FIG.102) with a first wing 1004 and a bolt 1006 which holds the first wingand the central body together. In this particular embodiment, thecentral body is made in two portions. The first portion 1102 is in theshape of a truncated cone with an oval or elliptical base and a secondportion 1104 includes a cylindrical central portion with a distal end inthe shape of a truncated cone 1103 with an oval or elliptical base. Inaddition, in this particular embodiment, formed with the central body isthe guide 1010 which has an oval or elliptical base. Bolt 1006 is usedto secure the first wing through the second portion 1104 with the firstportion 1102 held in-between.

In this particular embodiment, the guide 1010 in addition to includingrecess 1012 and bore 1014 includes a groove 1106 which receives aportion of the second wing 1032. In this particular embodiment, thesleeve 1016 is preferably oval or elliptical in shape as can be seen inFIG. 102 a. The central body can be oval, elliptical or circular incross-section, although other shapes are within the spirit and scope ofthe invention. The sleeve 1016 held in position due to the fact that thetruncated conical portion 1102 and the corresponding truncated conicalportion 1103 each have a base that is elliptical or oval in shape. Thus,the sleeve is held in position so that preferably the major dimension ofthe elliptical sleeve is substantially perpendicular to the majordimension of the first wing. It is to be understood that if the firstwing is meant to be put beside the vertebrae so that the first wing isset at an angle other than perpendicular with respect to the vertebraeand that the sleeve may be held in a position so that the majordimension of the sleeve is at an angle other than perpendicular to themajor dimension of the first wing and be within the spirit and scope ofthe invention. This could be accomplished by tightening bolt 1006 withthe first wing 1004 and sleeve 1016 so positioned. In such aconfiguration, the major dimension of the sleeve would be preferablypositioned so that it is essentially parallel to the length of theadjacent spinous processes. So configured, the elliptical or oval shapesleeve would bear and distribute the load more evenly over more of itssurface.

It is to be understood that the sleeve in this embodiment has all thecharacteristics and advantages described hereinabove with respect to theabove-referenced super-elastic sleeves.

The second wing as discussed above, can come in a variety of shapes inorder to provide for variations in the anatomical form of the spinousprocesses. Such shapes are depicted in FIGS. 103, 104, 105, 106, and107. In each configuration, the second wing 1032 has a upper portion1108 and a lower portion 1110. In FIG. 104, the lower portion is thickerthan the upper portion in order to accommodate the spinous process,where the lower spinous process is thinner than the upper spinousprocess. In FIG. 105, both the upper and lower portions are enlargedover the upper and lower portions of FIG. 103 to accommodate both theupper and lower spinous processes being smaller. That is to say that thespace between the upper and lower portions of the first and second wingsare reduced due to the enlarged upper and lower portions of the secondwing.

Alternative embodiments of second wings, as shown in FIGS. 104 and 105,are depicted in FIGS. 106 and 107. In these FIGS. 106 and 107, thesecond wing 1032 accommodates the same anatomical shape and size of thespinous processes as does the second wing in FIGS. 104 and 105respectively. However, in the embodiments of the second wing 1032 ofFIGS. 106 and 107, substantial masses have been removed from the wings.The upper and lower portions 1108 and 1110 are essentially formed orbent in order to extend from the central portion 1112 of the second wing1032.

It is to be understood that in this embodiment, if desired, the secondwing may not have to be used, depending on the anatomy of the spinalcolumn of the body, and this embodiment still has the significantadvantages attributable to the guide 1010 and the functionality of thesleeve 1016.

Embodiments of FIGS. 108, 109, and 110

The implant 1120 as shown in FIGS. 108 and 109, is similar to implant1100 which is in turn similar to implant 1000. Such similar details havealready been described above and reference here is made to the uniqueorientation of the first and second wings 1122 and 1124. These wingshave longitudinal axis 1126 and 1128 respectfully. As can be seen inthese figures, the first and second wings 1122, 1124 have been rotatedso that they both slope inwardly and if they were to continue out of thepage of the drawing of FIG. 108, they would meet to form an A-framestructure as is evident from the end view of FIG. 109. In thisparticular embodiment, as can be seen in FIGS. 109 and 110, the tab 1034is provided an acute angle to the remainder of the second wing 1124.Further, the groove 1018 formed in the implant is sloped in order toaccept the second wing 1124. Accordingly, this present implant 1120 isparticularly suited for an application where the spinous process iswider adjacent to the vertebral body and then narrows in size at leastsome distance distally from the vertebral body. It is to be understoodthat a cross-section of this implant 1120 through sleeve 1016 canpreferably be like FIG. 93 a.

Embodiments of FIGS. 111, 112, 113, 114, 115, 116, and 117

An additional embodiment of the implant 1150 is shown in FIG. 111.Implant 1150 has features similar to those described with respect toFIG. 94 b.

Implant 1150 includes a central body 1152 with a first wing 1154, wherecentral body 1152 includes elongated groove 1156 which extends to theguide 1158. A screw 1160 is received in a threaded bore located in theelongated groove 1156.

The second wing 1162 includes a central body 1164 which is substantiallyperpendicular to the second wing 1162.

The central body 1164 includes a plurality of bores 1166 providedtherein. These bores are formed adjacent to each other in order todefine a plurality of scallops, each scallop capable of retaining bolt1160 therein. As can be seen in FIG. 114, the second wing includes acut-out 1168 such that with the central body 1164 of the second wingreceived in the groove 1156 of the central body associated with thefirst wing, the remainder of the second wing is received over thecentral body 1152 of the implant 1150. With this implant 1150, thedistance between the first and second wings can be adjusted byselectively placing the bolt 1160 through one of the five specifiedbores defined by the scalloped plurality of bores 1166. Accordingly,FIG. 112 depicts the implant where the first and second wings are widestapart in order to accommodate spinous processes of greater thickness.FIG. 111 shows the middle position between the first and second wings inorder to accommodate average size spinous processes.

It is to be understood that preferably during the surgical process, thecentral body 1152 is urged between spinous processes. After this hasoccurred, the second wing is guided by the other sides of the spinousprocesses from a path which causes the plane of the second wing to movesubstantially parallel to the plane of the first wing until the centralbody 1164 associated with the second wing 1162 is received in the grooveof 1156 of the central body 1152 associated with the first wing 1154.After this has occurred, the bolt 1160 is positioned through alignedbores associated with the second wing 1162 and the central body 1152 inorder to secure the second wing to the central body.

While embodiment 1150 does not depict a sleeve such as sleeve 1016, sucha sleeve 1016 could be placed over body 1152 and be within the spirit ofthe invention.

Embodiments of FIGS. 119 a, 119 b, 120 a, 120 b, 121 a, 121 b, 122 a,122 b, 122 c, 123, 123 b, 124 a, 124 b, and 124 c

Implant 1200 of the invention is depicted in FIGS. 119 a and 119 b. Thisimplant includes the first wing 1202 and sleeve 1204 and a guide 1206.An alternative to this embodiment further includes, as required, secondwing 1208 as depicted in FIGS. 120 a and 120 b.

As can be seen in FIGS. 121 a and 121 b, the first wing 1202 includes abore which receives a central body 1210. Preferably, the central body ispressed fit through the bore of the first wing although it is to beunderstood that other securing mechanisms such as through the use ofthreads and still other mechanisms can be used to accomplish this task.Additionally, in this particular embodiment first and second pins 1212extend from the first wing 1202, each along an axis which issubstantially parallel to the longitudinal axis 1214 of the central body1210. In this particular embodiment, the distal end 1216 of the centralbody 1210 is threaded in order to be coupled to the guide 1206.

As can be seen in FIGS. 122 a, 122 b and 122 c, the guide 1206 in thisparticular embodiment is pointed in order to allow the implant to beinserted between, and if necessary distract, adjacent spinous processes.The guide 206 includes a threaded bore 1218 which is designed to acceptthe threaded end 1216 of the central body 1210 in order to secure theguide to the central body and additionally for purposes of retaining thesleeve between the guide 1206 and the first wing 1202.

As can be seen in FIG. 123 a the sleeve 1204 is preferably cylindrical,and oval or elliptical in shape in cross-section. It is to be understoodthat sleeve 1204 can have other shapes as described throughout thespecification and be within the spirit and scope of the invention. Inthis particular embodiment, sleeve 1204 has at least one major diameterand one minor diameter in cross-section. Sleeve 1204 includes a centralbore 1220 which extends the length of sleeve 1204 and curve grooves 1222which are formed about central bore 1220 and extend only part way intothe body of the sleeve. In this particular embodiment, the curvedgrooves 1222 describe an arc of about 60°. It is to be understood thatin other embodiment, this arc can be less than 60° and extend past 120°.

The sleeve 1204 is received over the central body 1210 of the implant1200 and can rotate thereon about the longitudinal axis 1214 of thecentral body 1210. When this particular embodiment is assembled, thegrooves 1222 have received therein the pins 1212 that extend from thefirst wing 1202. Accordingly, the pins inserted in the grooves 1222assist in the positioning of the sleeve relative to the remainder of theimplant 1200. With the pins 1212 received in the curved grooves 1222,the pins limit the extent of the rotation of the sleeve about thecentral body and relative to the first wing.

As can be seen in FIGS. 124 a, 124 b, and 124 c, the sleeve is free torotate relative to the longitudinal axis of the central body 1210 andthus relative to the first wing 1202 of the embodiment shown in FIGS.119 a and 119 b. The sleeve can rotate relative to a second wing 1208,when the second wing is utilized in conjunction with the embodiment ofFIGS. 119 a and 119 b. The pins limit the rotation of the sleeve. In analternative embodiment, the pins are eliminated so that the sleeve canrotate to any position relative to the first wing.

It is to be understood that the sleeve can be comprised of biologicallyacceptable material such as titanium. Additionally, it can be comprisedof super-elastic material such as an alloy of nickel and titanium, muchas described hereinabove with respect to other embodiments.

The great advantage of the use of the sleeve 1204 as depicted in theembodiment of FIGS. 119 a and 119 b is that the sleeve can be rotatedand repositioned with respect to the first wing 1202, and/or the secondwing 1208 should the second wing be used in the embodiment, in order tomore optimally position the implant 1200 between spinous processes. Itis to be understood that the cortical bone or the outer shell of thespinous processes is stronger at an anterior position adjacent to thevertebral bodies of the vertebra that at a posterior position distallylocated from the vertebral bodies. Accordingly, there is some advantageof having the implant 1200 placed as close to the vertebral bodies as ispossible. In order to facilitate this and to accommodate the anatomicalform of the bone structures, as the implant is inserted between thevertebral bodies and urged toward the vertebral bodies, the sleeve 1204can be rotated relative to the wings, such as wing 1202, so that thesleeve is optimally positioned between the spinous processes, and thewing 1202 is optimally positioned relative to the spinous processes.Without this capability, depending on the anatomical form of the bones,it is possible for the wings to become somewhat less than optimallypositioned relative to the spinous processes.

Embodiments of FIGS. 125, 126, and 127

FIGS. 125, 126 and 127 depict three alternative embodiments of theinvention as can be seen through a line parallel to line 124-124 of FIG.119 b.

In FIG. 125, the sleeve 1204 is rotatable about central body 1210. Inthis embodiment, however, the sleeve 1204 design does not include thegrooves 1222 as previously depicted in the embodiment shown in FIG. 123a. Thus, without pins, the sleeve is completely free to rotate about thecentral body 1210.

An alternative embodiment is shown in FIG. 126. In this embodiment, thesleeve 1204 is essentially a thin wall cylinder which is spaced from thecentral body 1210. Sleeve 1204 is free to move relative to central body1210. Sleeve 1204 can rotate relative to central body 1210. In addition,sleeve 1204 can take a somewhat cocked or skewed position relative tocentral body 1210.

A further embodiment, it is shown in FIG. 127. This embodiment issomewhat similar to the embodiment shown in FIG. 126 except that in thiscase, several pins project from the first wing in order to somewhatlimit and restrict the motion of the sleeve 1204. As shown in FIG. 127,four pins are depicted. It is to be understood however that such anembodiment can include one, two, three, four or more pins and be withinthe spirit and scope of the invention. It is to be understood that ifthe embodiment is used with a second wing, that similar pins can extendfrom the second wing. However, in the embodiment using a second wing,the pins would preferably be somewhat flexible so that they could snapinto the inside of the sleeve 1204 as the second wing is insertedrelative to the central body and secured in place. In the embodimentshown in FIG. 127, the sleeve 1204 is free to rotate about thelongitudinal axis of the central body 1210 and is somewhat restricted inthis motion and its ability to become skewed relative to thelongitudinal axis of the central body by the pins.

Embodiments of FIGS. 128 and 129

The embodiments of FIG. 128 is an advantageous alternative to that ofFIG. 93 a. In this embodiment, the central body 1002 is similar to thatas shown in FIG. 93 a. The sleeve 116 is comprised of two sleeveportions 1016 a and 1016 b. The sleeve portions are preferably formedfrom flat stock material which is substantially easier to form thanhaving the sleeve formed or machined from solid bar stock material. Afurther advantage of the sleeve 1016, if formed of super-elasticmaterial, is that the sleeve can be formed in a manner which optimizesthe super-elastic characteristics of such material in order to enhanceits ability to repeatedly deflect under load. In this particularembodiment, the sleeve portions 1016 a and 1016 b are somewhat C-shapedand then after being formed, are snapped into the grooves of the centralbody 1002.

An alternative embodiment of the invention is shown in FIG. 128. Thisembodiment is most favorably used with the embodiment of FIGS. 119 a and119 b. In this particular embodiment, the sleeve 1204 is designed torotate about the central body 1210. Sleeve 1204 includes a centralmember 1230 which includes a bore that receives the central body 1210.The central member 1230 is rotatable about the central body 1210 of theimplant 1200. The central member 1230 includes first and second grooves1232 and 1234. These grooves can receive C-shaped sleeve members 1204 aand 1204 b. These C-shaped sleeve members are similar in constructionand design to the C-shaped sleeve members shown above with respect toFIG. 128. These sleeve members can be snapped into position relative tothe central member 1230 of the sleeve 1204. It is to be understood thatother mechanisms can be used to secure the C-shaped sleeve memberrelative to the central member of the sleeve and be within the spiritand scope of the invention. Further, it is to be understood that thesleeve members 1204 a and 1204 b can be formed from a single flat stockmaterial such that one of the grooves 1232 and 1234 receives continuouspiece of flat material which has been appropriately bent and the othergrooves receives two ends of the sleeve.

Embodiments of FIGS. 130-136

Embodiment 2000 of the supplemental spine fixation device of theinvention is depicted in FIG. 130. This embodiment 2000 includes a hub2002 to which is adjustably secured a first hook member 2004 and asecond hook member 2006. First hook member 2004 includes a hook 2008which is more fully described hereinbelow, and a shaft 2010 extendingtherefrom. Similarly, second hook member 2006 includes a hook 2012 and ashaft 2014 extending therefrom. As described more fully hereinbelow,hook 2008 is swivelly or pivotably mounted to shaft 2010. It is to beunderstood that the description and functionality of first hook member2004 applies equally well to that of second hook member 2006. The shaft2010 in this embodiment includes a rack 2016 which can mate selectivelywith rack 2018 of hook member 2006. These two racks 2016 and 2018interlock in a multitude of positions in order to adjust the position offirst and second hook members 2004 and 2006, relative to each other andrelative to the hub 2002. The shafts 2010 and 2014 are positionedthrough bore 2020 in the hub 2002, selectively interlocked together andare then lockingly positioned using a locking mechanism such as thescrew 2022. As is described more fully below, the hooks 2008 and 2012are designed and shaped to fit around spinous processes. Further, thehooks 2008 and 2012 are swivelly mounted to the shafts 2010 and 2014 inorder to accommodate the various sizes, shapes, and positions of spinousprocesses of the human population.

Movably mounted to the hub 2002 is a shaft 2024 (FIG. 131) and extendingfrom the shaft 2024 is an inter-spinous process guide 2026. The shaft2024 at a proximal end includes a crossbar or tab 2028 which isslidingly or movingly received in a slot 2030 of the hub 2002. Once thetab 2028 is received in the slot 2030, the slot can be pinched off orslightly deformed at its open end using a punch or other mechanism inorder to prevent the tab 2028, and thus the shaft 2024 and the guide2026 from being removed from the hub 2002. With the tab 2028 located inthe slot 2030, the shaft and also the guide 2026 extending from thedistal end of the shaft 2024 are free to move relative to the hub andalso relative to the first hook member 2004 and the second hook member2006. This movement, as well as the ability of the hooks 2008 and 2012to swivel on the shafts 2010 and 2014, allow the embodiment 2000 toconform to the spinous process anatomy.

Movably mounted on the shaft 2024 is a spacer or sleeve 2032. Spacer2032 includes a central bore 2034 through which the shaft 2024 extends.The spacer 2032 is thus able to rotate about the shaft 2034. The spacer2032 is cylindrical and in this particular embodiment is oval orelliptical in shape. In addition, the base of the guide 2026 is alsosomewhat elliptical in shape in order to make a smooth transitionbetween the guide 2026 and the spacer 2032 as the guide and spacer areinserted between the spinous processes in order to distract apart thespinous processes during the insertion process. As the spacer 2032 isrotatable on the shaft 2024, and as the spacer 2032 is ellipticallyshaped, it can be inserted in one position and then as the entireembodiment 2000 is positioned to the final securing position, the spacer2032 can rotate about the shaft 2024 to accommodate the shape of thespace between the spinous processes as the spacer is moved from aposterior position to an anterior position.

The spacer 2032 can include a second alternative spacer embodiment 2036(FIG. 131 a) in substitution for the spacer 2032. Spacer 2036 includesan elongated slot 2038 into which the shaft 2024 can be received.Elongated slot 2038 not only allows the spacer 2036 to rotate about theshaft 2024, it also allows it to translate relative to shaft 2024. Suchtranslation in this embodiment is substantially perpendicular to theshaft, in any direction to which the spacer 2036 is rotated. Thus, inthis embodiment the degrees of freedom which accommodate the anatomicalshape of the spinous processes and the space therebetween, including theligaments and tissues associated therewith, include (1) the ability ofthe hooks 2004, 2006 to swivel on the shafts, (2) the ability of thehooks 2004, 2006 to move relative to the hub 2002 and be locked to thehub, (3) the ability of the shaft 2024 to move in the slot 2030 of thehub, and (4) finally the ability of the spacer 2036 to both rotate andtranslate on the shaft 2024.

Before proceeding to more specific details of this embodiment 2000, itis to be understood that the same features of the spacer, the shaft, andthe lead-in guide, which are found in other embodiments such as by wayof example only, the embodiments of FIGS. 10, 16, 20, 22, 86, 88, 92,and 119 b, and other figures, can be incorporated into this embodiment.By way of example only, the implant 2000 can be comprised of stainlesssteel, titanium or other biologically acceptable materials. The shape ofthe lead-in plug can be cone shaped, pyramid shaped, and other shapeswith a small lead-in cross-section expanding into a larger cross-sectionwhich is similar to the cross-section of the spacer 2032, in order togradually distract apart the spinous processes to a sufficient distanceso that the spacer 2032 or the spacer 2036 can conveniently fit betweenthe spinous processes. Further, the spacer, as shown in the otherembodiments, can include a spacer made of stainless steel or titanium,or of a super-elastic material or of a silicone. The spacer besidesbeing cylindrical can, from parallel planar end 2040 to parallel planarend 2042, be saddle-shaped along surface 2041 so that the ends are highand the center portions are low in order to more fully accommodate theshape of the spinous processes and also to spread the load across abroader contact surface between the spinous processes and the spacer.For example, the spacer 2032 could have a shape such as the saddle shapedefined by the mated together components of the embodiment of FIG. 16.Further, the dimensions of this embodiment as applied to the guide 2006and the spacer 2032 can be acquired from other embodiments presentedherein.

The shape of the guide 2026 and the spacer 2032 is such that forpurposes of insertion between spinous processes, the spinous processesto do not need to be altered or cut away in any manner in order toaccommodate this implant. Further, the associated ligaments do not needto be cut away and there would be very little or no damage to the otheradjacent and surrounding tissues. Similarly, the hook members 2004,2006, are appropriately shaped and also pivotable so that alteration ofthe spinous process is not required.

Returning to FIGS. 135 a-135 f and FIG. 136, the design of the hookmembers 2004 and 2006 are more fully depicted and described. Asindicated above, the description will be made with respect to first hookmember 2004. This description applies equally to second hook member2006. As can be seen in FIG. 135 b, the first hook member 2004 includesa shaft 2010 which is received in a bore 2044 of the hook 2008. Thisbore receives a rounded ball end 2046 seated against a somewhat circularseat 2048. A screw 2050 (FIG. 135 f) is received in the bore 2044 inorder to retain the rounded ball end 2046. The other end of the bore2044, end 2052, as can be seen in FIG. 135 f is oval or elliptical inshape. This allows the hook 2008 to swivel side to side on the shaft2010 in order to accommodate the spinous process while somewhatrestricting the back and forth rocking of the hook 2008 relative to theshaft 2010. This freedom of motion can be seen in FIG. 136 with respectto the upper spinous processes 2054. The hook can swivel side to side inorder to accommodate the shape of the upper spinous processes 2054. Thelower hook 2006 additionally can move in order to accommodate the lowerspinous processes 2056. As can be seen in FIGS. 135 c and 135 d, thehook 2008 can swivel about 15° on either side of a central longitudinalaxis of the shaft 2010.

Additionally with respect to the hook 2008, as can be seen in FIGS. 135a, 135 b, and 135 e, the hook includes a convex inner surface 2058 inorder to accommodate the varying surface shape of the spinous processes,and in order to even out the load transferred between the hook and thespinous processes.

The embodiment 2000 can be implanted in a number of methods, preferably,once a spine fixation device is implanted between the vertebral bodies.In this particular embodiment, through a small incision the hub, spacer,and guide are inserted with the guide and spacer inserted between thespinous processes. Once this is accomplished, a first hook member andthen a second hook member is secured about the respective spinousprocesses. The shafts of the hook members are then inserted through thebore of the hub 2002 until the spinous processes are brought tightagainst the spacer. The hooks are appropriately positioned on thespinous processes as depicted in FIG. 136. After this has beenaccomplished, the securing mechanism 2022 is tightened in order to lockthe hooks in place and to secure the spinous processes in a rigid mannerrelative to each other and relative to the distracting spacer 2032.Alternatively, the spinous ligaments can hold the spinous processestightly against the spacer and the hooks can be moved and locked intotight contact with the spinous processes.

The above procedure can have variations. By way of example only, thehooks can be inserted first through the incision and then the guide,spacer and hub can be inserted. Once this is accomplished the hooks canbe mated to the hub.

In another embodiment and method not depicted, the physician can insertthe shaft 2024 on which the spacer 2032 is mounted into the slot 2030 ofthe hub 2002 and can close off the slot with a securing screw in orderto retain shaft 2024. This process is in contrast to the shaft beingsecured in the slot during the manufacturing process. The securing screwwould be similar to securing screw 2022 and would be placed in a boremade at the top of slot 2030. The physician could accordingly insert thetab 2028 of the shaft 2024 in the slot 2030, and then secure the tab inplace with the securing screw.

Still an alternative method would be for the device 2000 to be insertedthrough a larger incision, with device 2000 fully assembled. Onceinserted the screw 2022 could be loosened so that the hook members couldbe positioned around spinous processes at about the same time that theguide and spacer are inserted between the spinous processes. Once thisis accomplished, the spinous processes could be drawn down tightlyaround the spacer, with the hooks tightly around the spinous processesand secured firmly into the hub 2002 with the securing screw 2022.

In all of the above procedures, it is advantageous that the device 2000can address the adjacent spinous processes from one side of the spinousprocesses and not require exposure of both sides of the spinousprocesses and thus the procedure is less traumatic to the surgical site.

Still an alternate insertion method would be to insert the device fullyassembled with the hook rotated at 90° to the final position shown inFIG. 130. Once the hooks are positioned adjacent to the spinousprocesses, the hooks could be rotated to the position shown in FIG. 130.Then simultaneously the guide and spacer could be inserted between thespinous processes, as the hooks are positioned about the spinousprocesses. The hooks are then drawn together, causing the spinousprocesses to be held firmly against the spacer. Once this isaccomplished the screw 2022 can be securely fastened to the hub 2002.

With respect to the embodiment of FIG. 130, this embodiment as fullydescribed above can be used as a supplemental fixation or augmentationdevice for the lumbar level fusion of the L4/L5 vertebrae and abovevertebrae, and also for the L5/S1 and below vertebrae. Thus, this device2000 can be used with respect to fusion of any of the vertebrae up anddown the spinous processes.

Embodiments of FIGS. 137-140

Another embodiment 2100 of the invention can be seen in FIGS. 137-140.Components and features of this embodiment 2100 which are similar tocomponents and features of the embodiment 2000 have similarly leastsignificant digits. Thus the hub for embodiment 2100 would be 2102. Themain difference between the embodiment 2100 and the previously describedembodiment 2000 is directed to the hub 2102 and the shafts 2110 and2114. In this embodiment, the shafts 2110, 2114 are substantiallyrectangular in cross-sections as opposed to semi-circular as in theprevious embodiment of FIG. 130. As can be seen in FIG. 138, shaft 2110is substantially rectangular in cross-section and include rack or teeth2116. Shaft 2114 is shaped as a fork with two tines 2115 and 2117.Further, the two tines have rack or teeth 2118. The shaft 2110 of thefirst hook member 2104 slides between the two tines 2115 and 2117. Ascan be seen in FIG. 139, with the shaft 2110 slipped between the twotines 2115, 2117 and also with shafts 2110, 2114 located in therectangular bore 2120 of the hub 2102, the top cap 2103 (which is shownboth from the top side (FIG. 138) and from the bottom side (FIG. 138 b))can be placed over the hub 2102. The teeth or rack 2105 on the bottomside of the cap 2103, mesh with the teeth or rack 2116 and 2115, 2117 ofthe first and second hook members. Once this is accomplished, the screw2122 can be inserted through the indicated bore so that the cap 2103 cantighten down on the hub 2102, locking the shafts 2110 and 2114 of thefirst and second hook members in place.

All the other features, dimensions, characteristics, materials, methodsof insertion, and methods of operation of the embodiment shown in FIG.138 are similar to or derivations from that shown in the embodiment ofFIG. 130.

Embodiments of FIGS. 141-143

Another embodiment of the invention is depicted in FIGS. 141-143. Thisembodiment is similar to the other embodiments 2000 and 2100. Thisembodiment is numbered 2200. Similar elements, features, methods andaspects have similar numerical designations with respect to the lowesttwo significant digits. Thus the hub of embodiment 2200 is identified ashub 2202.

In this particular embodiment, the hub has rigidly affixed thereto shaft2224. Here shaft 2224 does not slide in a slot as happens with respectto the prior two embodiments 200 and 2100. Shaft 2224 can be screwedinto hub 2202 or integrally formed with hub 2202. Additionally, theguide 2226 can be integrally formed with the shaft 2224 or in othermanners fastened to the shaft 2224 as with a thread mechanism. In thisparticular embodiment, as can be seen in FIG. 143, the shaft 2224 isintegrally formed with the hub 2202 and the shaft 2224 includes athreaded extension 2225 onto which is screwed the guide 2226. For thisparticular embodiment, the sleeve or spacer 2236 includes the elongatedslot 2238 in order to provide for freedom of movement between the sleeveor spacer 2236, the hub 2202, and the first and second hook members 2204and 2206.

In this particular embodiment the shaft 2210 and 2214 are similar tothose depicted with respect to the embodiment 2000. In other words eachhas a rack or teeth which mate with the other. Shafts 2210 and 2214 areinserted through the semi-circular bore 2220 of the hub 2202, and thenthe cap 2203 is mated on top of the hub 2202. The cap includes asemi-circular bore 2207 which is positioned over the upper shaft 2210.Both bores 2207 and 2220 include ribs, teeth, or threads that run alongthe length of the bores. These ribs, teeth, or threads are urged againstthe shafts in order to assist in locking the shafts in place.Alternatively, the ribs, teeth, or threads of the bores can be acrossthe length of the bores. The shafts 2210 and 2214 can have teeth, ribs,or threads that are positioned all about the shafts so that the shaftscan lock to each other, and so that the teeth, racks or threads on thebores can lock the shafts in place. Once the cap 2203 is positioned overthe hub 2202, the screw 2222 is positioned in the bore of the hub 2202in order to lockingly position the first and second hook members 2204and 2206 relative to the hub. In particular, with respect to embodiment2200, the degrees of freedom are attributable to (1) the slot 2238 inthe spacer 2236, (2) the shafts 2210 and 2224 which can be positionedrelative to each other to position the hooks 2204 and 2206 relative tothe hub, and accordingly relative to the spacer, and (3) the ability ofthe hooks 2204 and 2206 to swivel or pivot.

As indicated above, all the other features, materials, aspects,dimensions, and so forth, of the embodiment 2200 are similar to and canbe specified according to the other embodiments 2000 and 2100.

A preferred method of insertion of this embodiment 2200 into a patientis as follows. Initially through a small incision the guide, spacer andhub are inserted so that the guide is positioned between and distractsapart adjacent spinous processes, allowing the spacer to come betweenthe spinous processes. The spacer and guide can be moved in a posteriorto anterior direction, and the spacer is able to rotate and translate inorder to accommodate such movement. After this is accomplished, thefirst and second hook members are positioned through the incision andaround upper and lower spinous processes. Once that is accomplished, thespinous processes are urged towards each other and about the spacer, ifthis is not already the condition caused by the insertion of the spacerin order to distract the spinous processes. Then the racks of the shaftsare meshed together, and the cap is placed upon the hub in order tosecure the hooks firmly to the hub and thus to secure the spinousprocesses rigidly in position about the spinous processes.

Embodiments of FIGS. 144-146 c

A further embodiment 2300 of the invention is depicted in FIG. 144. InFIG. 144, the hub 2302 of this embodiment is depicted. This hub could beused, for example, with the embodiment shown in FIG. 141 and similarcomponents are similarly numbered. In this embodiment, the hub 2302includes an integral shaft 2324 with a threaded end 2325 which canaccept a guide such as guide 2226 of FIG. 141. Unlike the embodiment inFIG. 141, this hub 2203 does not have a cap. Instead hub 2302 includesan open bore 2320 which is shaped in order to receive shafts 2310 and2314, which have mating notches or teeth. Bore 2320 has a portion 2321which is circular and which receives the mated shaft 2310, 2324.

Once this is accomplished, a screw 2322 is received in the threaded bore2323 in order to lockingly position the mated shafts 2310, 2324. As thisembodiment has an open bore 2320 and no cap, mating of the shafts 2310,2314 to the open bore 2320 of the hub 2302 can be done quickly andefficiently.

FIG. 145 shows a hub 2402 of an embodiment 2400. This hub 2402 issimilar to hub 2302, with the open bore 2420 having a shape which isdifferent from the shape of bore 2320. In this embodiment bore 2420includes a flat 2421 and a circular portion 2423. The shafts 2410 and2414 when mated together would register in this open bore 2420. Inparticular, shaft 2414 has a flat which mates to flat 2421 and thecombined shafts 2410 and 2424 have a circular portion which would mateto the circular portion 2423 of the bore 2420. Otherwise, hub 2202 wouldfunction similarly to hub 2302.

FIGS. 146 a, 146 b, and 146 c depict a hub arrangement 2502 of anembodiment 2500 of the invention. In this embodiment, hub 2502 has twocomponents 2511 and 2513. Component 2511 includes an open bore 2520which is specially shaped in order to register shafts 2510, 2514 of thefirst and second hook members. In this particular embodiment, shaft 2510is semi-circular in cross-section while shaft 2514 is triangular-shapedin cross-section. The triangular shape of shaft 2514 mates with thecorner 2525 of the open bore 2520. The term open bore refers to 2520 andalso to bores 2320 and 2420 in FIGS. 144 and 145, and means that notonly are both ends of the bore open, but there is a longitudinal slotalong the length of the bore which is open, allowing access to the borefrom the side of the bore. Once the shafts 2510, 2514 are inserted asshown FIG. 146 c, a screw 2522 can be tightened through a bore of thehub 2502, locking the shafts in place. Once this has occurred, the firstportion 2511 of the hub 2502 can be mated into the second portion 2513of the hub 2502. In this embodiment, the second portion of the hub 2513includes a slot 2515 into which can be slid or snapped into the firstportion 2511. The first portion 2511 includes tangs 2517 and 2519 whichfit under lips 2521, 2523 respectively as the first portion 2511 of thehub 2502 is slid or alternatively snapped into engagement with thesecond portion 2513. Once this occurs, a locking cam 2527 is turned inorder to cause a cam member to be urged against this portion 2511 of thehub in order to lock 2511 to the second portion 2513. Alternatively, itis to be understood that the act of sliding or snapping hub portion 2511into hub portion 2513 can be sufficient to lock portion 2511 intoportion 2513. This embodiment further includes spacer 2536 and coneshaped guide 2526.

Other features, functions, dimensions, and so forth of this embodimentare similar to the other embodiments as, for example, the embodiment ofFIG. 141.

For purposes of insertion, one insertion methodology can be to insertthe second hub portion 2513 with the guide 2526 into the positionbetween the spinous processes. After this is accomplished, the hookmembers can be positioned about the spinous processes and locked intothe first hub portion 2511. Then the first hub portion 2511 could beslid or snapped into engagement with the second hub portion 2513.Following that, the cam 2527 can be turned in order to secure the firsthub portion 2511 to the second hub portion 2513.

Embodiments of FIGS. 147 a-149 b

FIGS. 147 a and 147 b depict another embodiment 2600 of the invention.This embodiment 2600 includes a hub 2602 and a rack and pinionarrangement. The rack and pinion arrangement includes first and secondpinions 2660 and 2662. These pinions engage shafts 2610 and 2614respectively. In these embodiments, these shafts 2610 and 2614 haverounded ends to which the hook is secured as depicted in, for example,FIG. 131. For simplicity, these hooks have been left off of FIGS. 147 a,147 b. The position of the shafts 2610 and 2614 can be adjusted relativeto the hub. Once the shafts 2610, 2614 are appropriately positioned thepinions can be locked in position, locking the shafts in position.Pinions can be locked in position by tightening down screws such asscrew 2664 against the pinion 2660. A similar screw, not shown, wouldtighten down pinion 2662.

Another embodiment of the invention, embodiment 2700 is depicted inFIGS. 148 a and 148 b. In this embodiment a bevel gear arrangement 2770is contained in the hub 2702. Bevel gear arrangement 2770 includes afirst bevel gear 2772 and a second bevel gear 2774. Bevel gear 2772 hasa shaft 2776 extending therefrom with a slot 2778. Slot 2778 can receivea tool for turning the bevel gear 2772. Bevel gear 2774 is mated to athreaded shaft 2710 of the hook member 2704. In this particularembodiment, the hook is not shown as is the case for the embodiment ofFIGS. 147 a and 147 b. When the bevel gear 2772 is turned, it turnsbevel gear 2774. The turning of bevel gear 2774 causes the threadedshaft 2714 to retreat into or extend out of the center of the othershaft 2710. With the hook members positioned around spinous processes,the bevel gear 2772 can be used to turn bevel gear 2774 in order to drawthe hook member 2706 toward the hub 2702, tightening the hook membersabout the spinous processes.

In this embodiment 2700, a shaft 2724 extends therefrom in order toreceive a spacer and a guide in the same manner that, for example, theembodiment of FIG. 144 receives a spacer and a guide.

FIGS. 149 a and 149 b depict embodiment 2800 of the invention.Embodiment 2800 includes a hub 2802 which houses a turnbucklearrangement 2880 which is actuated by a worm gear drive 2882. Turnbuckle2880 receives the threaded shaft 2810 and 2814 of the hook members 2804,2806 respectively. As with the past embodiments, the actual hooks ofthese hook members are not depicted in order to simplify the drawing. Byturning the turnbuckle 2880, the threaded shafts 2810, 2814 are eitherdrawn into or urged out of the turnbuckle. Thus, by turning the wormgear 2882 with a tool placed in the slot 2884, the turnbuckle turns,causing the hook members to extend out of or be urged into the hub 2802.

Extending from the hub is a shaft 2824 with a threaded end 2825. As withthe other embodiments, such as the embodiment in FIG. 144, a spacer canbe placed on the shaft 2824 and a guide can be placed on the threadedend 2825.

The preferred method of inserting this embodiment is to insert theembodiment as a whole, placing the guide and spacer between the spinousprocesses. The hooks would be initially rotated 90° from their finalorientation. Once inserted adjacent to the spinous processes, the hookswould be rotated by 90° and the spacer and the hooks would be furtherurged into contact with the spinous processes. Once this has occurred,the turnbuckle would be turned in order to tighten the hooks about thespinous processes.

Embodiment of FIG. 150

Another embodiment 2900 of the invention is depicted in FIG. 150. Thisembodiment is similar to several of the other embodiments and, inparticular, to the embodiment shown in FIG. 130. Accordingly, similarelements will have similar least significant numbers. By way of example,the hub is designated 2902. In this particular embodiment, the hub iscomprised of two components, the first hub component 2911 and the secondhub component 2913. This is somewhat similar to the hub components shownin FIG. 146 b.

The two hook members are secured to the first hub component 2911 in muchthe same manner as the hook members of FIG. 130 are secured to the hubin FIG. 130.

The hub 2902 is divided into first hub component 2911 and second hubcomponent 2913 in order to add flexibility in the positioning of theguide and spacer fitted to second hub component 2913 with respect to thefirst and second hook members 2904 and 2906 which are secured to thefirst hub component 2911. Thus, should the anatomy of the spine and inparticular the spinous process require, the spacer 2936 and the guide2926 can be moved relative to the first and second hook members 2904 and2906 by selectively positioning the second hub component 2913 relativeto the first hub component 2911. This can be accomplished by aligningthe bore 2980 over one of the plurality of bores 2982 positioned throughthe first hub component 2911. After this is accomplished, a threadedscrew 2984 can be inserted through smooth bore 2980 and engage one ofthe threaded bores 2982 in order to secure the second hub component 2913to the first hub component 2911, thus positioning the sleeve or spacer2936 in a desired location relative to the first and second hookmembers.

Embodiment of FIG. 151

Yet another embodiment of the invention 3000 is depicted in FIG. 151.Embodiment 3000 is meant for a double level spinous process fixation.That is to say that three spinous processes are engaged and rigidlyfixed together. Such a situation would occur, for example, when there isa double level primary fusion. That is, three adjacent vertebral bodiesare all fused together. In such a situation a double level supplementalspine fixation device 3000 would be used. This embodiment 3000 could bedesigned using any of the other embodiments depicted heretofore.Embodiment 3000 is in this particular instance modeled after theembodiment 2000 shown in FIG. 141. Accordingly, the elements that aresimilar to FIG. 141 have similarly least significant digits. By way ofexample, the hubs of FIG. 151 are both designated 3002 in accordancewith the designation of FIG. 141. Similarly, the hub caps, sleeves, hookmembers, spacers, and guides are similarly numbered. In this embodimenttwo hubs, two spacers, and two guides are required as the first guide3026 and the spacer 3036 would be inserted between first and secondspinous processes, while the second guide 3026 and spacer 3036 would beinserted between the second and third spinous processes. The hookmembers 2004 and 2006 would hook about the first spinous process and thethird spinous process respectively.

A preferred method of insertion of the device relative to three spinousprocesses would be to insert the guides and spacer between the first andsecond, and then the second and third spinous processes in order todistract apart the first and second spinous processes and also todistract apart the second and third spinous processes. After this isaccomplished, the first hook member would be placed about the firstspinous process and the second hook member would be placed about thethird spinous process. The shafts of the hook members would be insertedin the respective hubs 3002. In this situation, the shafts are bothup-facing racks or teeth as shown in FIG. 151. A linking shaft 3039 hasdownwardly facing racks or teeth. Thus the upwardly facing rack or teethof the first hook member 2004 would be laid in the upper hub 3002 withthe teeth facing up. The teeth of the member 3039 facing down wouldengage the rack or teeth of the first hook 2004. Once this isaccomplished, the cap will be placed over the hub and the screw insertedin order to rigidly secure the hook member and the shaft 3039 relativeto the upper hub 3002. Then the shaft of the second hook 2006 would bepositioned in the lower hub 3002. The rack of shaft 3039 would mesh andlock with the rack of the shaft of the second hook member 2006. Oncethis is accomplished, the cap 3203 would be placed over the hub and thescrew would be inserted through the cap into the hub in order to securethe shaft 3039 and the second member 2006 relative to the lower hub.

Embodiments of FIGS. 152-160

An alternate embodiment 3100 of the supplemental spine fixation deviceof the invention is depicted in FIG. 152. This embodiment 3100 includesa hub 3102 to which is adjustably secured a first hook member 3104 andsecond hook member 3106. First hook member 3104 includes a hook 3108which is more fully described herein below, and a shaft 3110 extendingtherefrom. Similarly, second hook member 3106 includes a second hook3112 and shaft 3114 extending therefrom. Shaft 3110 and 3114 areassembled together in a manner as will be described hereinbelow.

As described more fully below, hook 3108 is swivelly or pivotallymounted to shaft 3110. It is to be understood that the description andfunctionality of the first hook member 3108 applies equally well to thatof the second hook member 3106. The shaft 3110, onto which hook 3108 ismounted in this embodiment, is received inside of the shaft 3114. Shaft3110 can extend from shaft 3114 in a telescoping or sliding mannerrelative to shaft 3114 or alternatively shaft 3110 can be threaded intoshaft 3114 and the rotation of shaft 3110 would allow it to extend fromor be retracted into shaft 3114. Shafts 3110 and 3114 are received in abore 3120 of the hub 3102. In this particular embodiment shaft 3114 canbe press fit or otherwise secured in bore 3120. Shaft 3110 is thus freeto move relative to the hub 3102 and the shaft 3114, until the hub 3102is assembled, locking shaft 3110 into position in this particularembodiment. This locking arrangement will be discussed more fully below.

The hooks 3108 and 3112 are designed and shaped to fit to spinousprocesses. Further the hooks 3108 and 3112 are swivelly mounted to theshafts 3110 and 3114, respectively, in order to accommodate the varioussizes, shapes, and positions of the spinous processes of the humanpopulation.

Swivelly mounted to the hub 3102 is a shaft 3124, and extending from theshaft 3124 is an inner-spinous process guide, or lead-in nose, or tissueexpander 3126. The shaft 3124 at its proximal end includes a ball 3125,which is received in socket 3127 which is formed by the two portions ofthe hub 3102. At this ball and socket mechanism, the shaft 3124 ispivotable with respect to the hub 3102. With this arrangement, thetissue expand 3126 has some freedom of movement with respect to the hub3102. The other end of the shaft 3124 (FIG. 154 a) also includes a ball3129 which fits into a socket arrangement 3131 created in the guide ortissue expander 3126. This arrangement allows the guide or tissueexpander 3126 to pivot with respect to the shaft 3124. Accordingly theshaft 3124 is free to pivot relative to the hub and the guide or tissueexpander 3126 is free to pivot relative to shaft 3124. This movement, aswell as the ability of hooks 3108 and 3112 to swivel on the shaft 3110and 3114, and the ability of the shaft to be positioned relative to eachother allows the embodiment 3100 to conform to the spinous processanatomy.

In this particular embodiment, a sleeve or spacer 3132 is pivotallymounted on the shaft 3124 along with the guide 3126. In otherembodiments as described below, the sleeve spacer 3132 is free to rotaterelative to the guide 3126. Spacer 3132 includes a central bore 3134 inwhich the shaft 3124 extends. The spacer 3132 as well as guide 3136 arethus able to pivot and rotate about the shaft 3124. The spacer 3132 inthis embodiment is cylindrical and in this particular embodiment is ovalor elliptical in shape. For such shapes, the spacer can have minordiameters of 6 mm, 8 mm, 10 mm, and 12 mm. Smaller and larger diametersare within the spirit and scope of the invention. In addition, thespacer can be egg shaped as more fully described below. Further, thebase of the guide 3126 is somewhat elliptical in shape in order to makea smooth transition between the guide 3126 and the spacer 3132 as theguide and spacer are inserted between the spinous processes in order todistract apart the spinous processes. As the guide 3126 and the spacer3132 are rotatable and pivotable on the shaft 3124, and as the spacer3132 is elliptically shaped, it can be inserted into one position andthen as the entire embodiment 3100 is positioned to the final securingposition, the spacer 3132 can be rotated about the shaft 3124 andpivoted relative thereto in order to accommodate the shape of the spacebetween the spinous processes as the spacer is moved generally from aposturing position to an anterior position closer to the spine.

As can be seen in FIG. 152 and also in FIGS. 154 a and 154 c, thecentral bore 3134 of the spacer 3132 has a first end 3133 which isenlarged and in this particular embodiment substantially elliptical inshape. The second end 3135 is smaller. The reason for this arrangementis most evident in FIGS. 154 a and 154 b where in phantom variouspositions of the shaft 3124 are depicted demonstrating the pivotabilityof the guide 3124 and the sleeve 3132 relative to the hub 3102. As canbe seen in FIGS. 154 a and 154 c, in this particular embodiment, theshaft 3124 is inserted into the small end 3135 of the sleeve 3132. Aretainer 3137 is inserted relative to the ball 3129 of the shaft 3124.The lead-in nose or tissue expander 3126 is then inserted over the smallend 3139 of the sleeve 3132 and pin 3141 is inserted into aligned slotsin the guide 3126 and the sleeve 3132 in order to assemble togetherguide 3126, the retainer 3137 and the sleeve 3132 about the ball 3129 ofthe shaft 3124 to create a ball and socket arrangement, whereby theguide 3126 and sleeve 3132 are pivotable and rotatable about the ball3129.

The spacer 3132 can include an alternate embodiment spacer 3136 as shownin FIG. 160. This spacer 3136 can be substituted for spacer 3132. Spacer3136 includes an egg-shape cross-section with a central bore 3138 uponwhich the shaft 3124 can be inserted so as to allow the spacer 3136 torotate about the shaft 3124. As can be seen in FIG. 160, the egg-shapedspacer 3136 has a blunt end 3143 and a pointed end 3145. The center ofthe bore 3138 is off-center and more towards the front end 3134 in thispreferred embodiment allowing the pointed nose end 3145 to bepositionable more closely to the spine. This allows the flat sides 3147,3149 between the blunt end 3143 and pointed end 3145 to be positionedcloser to the spine and adjacent to portions of spinous processes whichare generally comprised of stronger bone. In addition, these flat sides3147 and 3149 can more easily accommodate and carry and thus spread theload placed thereupon by the adjacent spinous processes. The bore 3138can be shaped like bore 3134 (FIG. 154 c) to allow for pivoting androtating motion. Also, in order to accommodate bore 3138 of theegg-shaped spacer 3136 being off-center, the lead-in guide 3126 wouldalso be egg-shaped and have an off-center position where shaft 3124 isattached.

In another arrangement, the embodiment as shown in FIG. 154 c could bemodified to so that the small end 3139 of the spacer 3132 or of thespacer 3136 is severed from the remainder of the spacer 3132, 3136 andpinned by itself to the guide 3126 in order to capture the ball of theshaft. Thus the remainder of the spacer 3132, 3136 could rotate free ofguide 3126.

Before proceeding to more specific details of this embodiment 3100, itis to be understood that the same features of the spacer, the shaft, andthe lead-in guide, which are found on other embodiments such as by wayof example only the embodiments of FIGS. 10, 16, 20, 22, 86, 88, 92 and119 b, and other figures can be incorporated into this embodiment. Byway of example only, the implant 3100 can be comprised of stainlesssteel, titanium, or other biologically acceptable materials. The shapeof the lead in plug can be cone shaped, pyramid shaped and other shapeswith a small lead in cross-section expanding into a larger cross-sectionwhich is similar to the cross-section of the spacer 3132, in order togradually distract apart the spinous processes to a sufficient distanceso that the spacer 3132 or the spacer 3136 can conveniently fit betweenthe spinous processes. Further, the spacer, as shown in the otherembodiments, can include a spacer made of stainless steel or titanium orof a super-elastic material or of a silicone. The spacer besides beingcylindrical, can be saddle-shaped along the surface which engages thespinous processes so that the high edges and the lower central portionscan more fully accommodate the shape of the spinous process. This shapealso aides in spreading the load across the broader contact area betweenthe spinous processes and the spacer. For example, the spacer 3132 or3136 could have a shape such as the saddle shape defined by the matedtogether components of the embodiment of FIG. 16. Further, dimensions ofthis embodiment as applied to the guide 3106 and the spacer 3132 can beacquired from other embodiments presented herein. By way of exampleonly, the guides and spacers can have multiple shapes with the smalldiameter of the elliptical shape being on the order of 6 mm, 8 mm, 10mm, 12 mm and 14 mm.

The shape of the guide 3126 and the spacer 3132 or the spacer 3136 issuch that for purposes of insertion between the spinous processes, thespinous processes do not need to be altered or cut away in any manner inorder to accommodate this implant. Further, the associated ligaments donot need to be cut away and there would be very little or no damage tothe other adjacent and surrounding tissues. Similarly, the hook members3104 and 3106 are appropriately shaped, as described below and are alsopivotable so that alterations of the spinous processes is not required.

Referring to FIG. 155 a through 155 e, the design and shape of the hook3108 is more fully described and depicted. As indicated above, thedescription will be made with respect to the first hook 3108. Thisdescription applies equally well to second hook 3112. As can be seen inFIG. 155 a, the first hook 3108 includes a bore 3144 into which theshaft 3110 is received. The shaft has a rounded end which has a boreprovided therethrough. This bore mates with the bore 3145 associatedwith the bore 3144 of the hook 3108. When the bore of the shaft 3110 andthe bore 3145 of the hook are aligned, a pin or screw can be inserted inorder to lock the hook 3108 onto the shaft 3110. As can be seen in FIG.155 d, the lower end 3147 of the bore 3144 is oval or ob-round in shapeallowing for the shaft to be pivotally received in the bore. Thus thehook 3108 is pivotable with respect to the end of the shaft 3110. Thehook thus can pivot in order to accommodate the shape of the spinousprocess. Turning to FIG. 155 a, the lead in nose or guide or tissueexpander 3150 of the hook 3108 is pointed as can be additionally seen inFIGS. 155 d and 155 e. This allows the guide 3150 to be easily insertedbetween spinous processes and spread the tissue so that the concaverecess 3152 can be received over the spinous process. The hook is thenlocked on the spinous process in order to retain the hook 3108 in placeadjacent to the spinous process. The recess 3152 has a cross-sectionwhich is convex in shape in order to accommodate the various surfaceshapes of the spinous process and in order to even out the load transferbetween the hook and the spinous process.

Again with respect to the lead in nose 3150 in a preferred embodiment,this nose is essentially shaped in the form of a pyramid with all of itssides rounded and curved. This allows the nose 3150 to easily beinserted over and past the spinous process, until the concave recess3152 rests over the spinous process with the hook element 3154 caught bythe spinous process in order to retain the hook 3108 in place.

As can be seen in FIG. 153, the hub 3102 is comprised of two portions.The lower hub portion 3103 receives the shaft 3110 and 3114. The lowerportion 3103 also receives the shaft 3124 upon which the nose and sleeveare mounted. The upper portion 3105 of the hub 3102 mates with a lowerportion 3103 in order to lock the shaft 3110 and the shaft 3124 inplace. The upper hub portion 3105 is secured to the lower portion 3103with a screw through threaded bore 3107. As can be seen in FIG. 157,upper hub portion 3105 includes a locking projection 3109. This lockingprojection includes a concave surface. The locking projection 3109, withthe upper hub portion 3105 is mated to lower hub portion 3107, bearsdown upon the shaft 3110 to lock it in position. Upper hub portion 3105also includes a half spherical captured enclosure 3111. With the hubportions assembled, the enclosure 3111 captures the ball end of shaft3124. It is to be understood that with respect to the embodiment of FIG.153, that with the two halves of the hub 3102 mated together, aspherically shaped capture enclosure captures the ball end of shaft3124.

FIGS. 158 a and 158 b depict alternative embodiments of a hubarrangement. This alternative hub 3160 includes lower hub portion 3162and upper hub portion 3164. In this embodiment, the ball end of theshaft 3124 is captured in the lower half of the hub 3160. The upper half3164 of the hub is mated to the lower half with a screw 3166 which isplaced through a leaf spring 3168 carried with the screw 3166. The leafspring bias the upper hub portion 3164 towards the lower hub portion3162 in order to trap and capture the shaft 3114. Once this isaccomplished, the screw 3166 is tightened in order to complete theassembly.

FIG. 159 depicts yet an alternate embodiment of the hook and shaftarrangement which could be used instead of, by way of example only, hook3108 and shaft 3110. In this arrangement the hook 3170 includes a bore3172 which goes completely through the hook 3170. Both ends of the ovalare oval or ob-round in order to allow the hook 3170 to pivot on shaft3174. Shaft 3174 has a plurality of bores 3176 provided therethrough,any one of which can align with the bore 3178 which is provided acrossthe bore 3172 of the hook 3170. When such an alignment is made a pin orscrew can be inserted into bore 3178 in order to secure the shaft 3174to the hub 3170. By selecting one of the several bores 3176 in the shaft3174, the position of the hook relative to the hub can be adjusted inorder to accommodate the shape and spacing of the various spinousprocesses.

Embodiment 3100 can be implanted in a number of methods in accordancewith the teachings for the implantation of the embodiment 2000.Preferably this would occur once a spine fixation devices is implantedbetween the vertebral bodies in order to fuse together adjacentvertebral bodies.

In one preferred embodiment of implantation, in particular with respectto the embodiment of FIG. 153, the guide and sleeve or spacer can beinserted between adjacent spinous processes. Once this is accomplished,the hooks at the end of shafts could be positioned relative to the hub3102 so that the hooks can grab about adjacent spinous processes. Oncethis has occurred, the shaft 3124 can be received in the lower portionof the hub. The upper portion of the hub 3105 can be mated with thelower portion in order (1) to capture and fix shaft 3124 in place,allowing for the movement of the shaft 3124, and also (2) to capture andfix the shaft 3110 in place to rigidly position the shaft 3110 relativeto the hub 3102.

It is also to be understood that in other situations the fully assembledembodiment can be inserted in place relative to the adjacent spinousprocesses. Once this accomplished, a screw such as the screw in FIG. 153can be tightened in order to secure the various shafts relative to thehub 3102.

In all of the above procedures, and also in the procedures with respectto prior embodiment 2000, it is advantageous that the embodiments canaddress the adjacent spinous processes from one side of the spinousprocesses and do not require exposure to both sides of the spinousprocesses. Thus, this procedure is less traumatic to the surgical site.

INDUSTRIAL APPLICABILITY

From the above, it can be seen that the present invention can be used tosuccessfully provide for supplemental spine fixation as an adjunct toprimary spine fixation. Also spinous fixation without vertebral bodyfusion could be accomplished if that is desired. The embodiments of theinvention provides the correct amount of rigidity between spinousprocesses with a minimally invasive device and methodology. The presentinvention does not require that structures associated with the spinousprocess, including bone and ligament, be altered for purposes ofimplantation, thus the device and method do not add to the traumaassociated with spinal fusion.

Other features, aspects and objects of the invention can be obtainedfrom a review of the figures and the claims.

It is to be understood that other embodiments of the invention can bedeveloped and fall within the spirit and scope of the invention andclaims.

1. A method of stabilizing at least one spinal motion segment includinga first vertebra having a first spinous process and a second vertebrahaving a second spinous process, wherein an interspinous space isdefined therebetween, comprising: inserting a device having a firstforked end and a second forked end into the interspinous space such thatthe first forked end is adapted to receive the first spinous process andthe second forked end is adapted to receive the second spinous process;the device further comprising an intermediate body distinct from boththe first forked end and the second forked end and disposed between thefirst forked end and the second forked end; wherein the first forked enddefines a first location and the second forked end defines a secondlocation such that the first location is located a first distance fromthe second location during the insertion step; moving the first locationto a second distance from the second location wherein the seconddistance is greater than the first distance; engaging the first spinousprocess with the first location and engaging the second spinous processwith the second location; thereafter, moving the first location to athird distance from the second location wherein the third distance isgreater than the second distance; wherein the moving the first locationto a third distance comprises both: rotating the intermediate bodyrelative to the first forked end to engagingly move male and femalethreads relative to each other; and rotating the second forked endrelative to the intermediate body without longitudinally displacing thesecond forked end relative to the intermediate body; wherein theintermediate body has a substantially cylindrical exterior surface;wherein the second forked end comprises a hollow shaft portion disposedin a bore of the intermediate body; the intermediate body disposedoutside of the second forked end such that the intermediate bodyexternally overlaps the shaft.
 2. The method of claim 1 wherein the stepof moving the first location to a third distance from the secondlocation comprises exposing more of the male threads.
 3. The method ofclaim 1 further comprising allowing the spinal motion segment to adjustto the magnitude of the second distance before moving the first locationto a third distance from the second location.
 4. The method of claim 3wherein the device is not fixed with respect to the spinal motionsegment.